I would not assume coworker is stealing, she may just assume it is community property. I second the idea of putting it in a thermos with your name on it, or into a small thermal lunch bag. Anything that would make it look more like personal item vs. community property.
I think people need to vent!
““Eats everything that doesn’t eat her first” - that sounds a bit harsh!”
That the definition of an omnivore. 
Agree that personalization is key here. Thermos, cooler, some sort of a carton wrap… But some folks will dip into personal stashes of others, no matter how personal those stashes are… Like the VP at one of my old co’s who was notorious for his late night fridge raids and who once ate my clearly marked leftover Mexican food… Put the empty styrofoam box with a plastic fork inside back into the fridge. LOL!!!
How about printing this and posting it in the kitchen? 
http://www.emilypost.com/on-the-job/office-issues/907-the-office-kitchen?format=pdf
Since it is such a small office you could mention that you are bringing in a couple of things for a special diet and you can label these things and you’d appreciate it if people do not use them. And also tell them that you appreciate their supporting you in this effort.
Wait until you are in the kitchen with her and take a big gulp directly from the container. Then just put the container back.
put it in a container marked “breast milk”.
Especially since it is a small office and because whipping cream isn’t THAT expensive given how much is used in a cup of coffee, if it was me, I’d leave it alone and just buy enough to share. If the usage becomes more frequent or excessive and it really bothers you, then perhaps you address it. Personally, I wouldn’t as it would not be worth it to me for such a low cost item. I’m all for sharing in the workplace. It creates a more harmonious environment to let the little things slide.
Your post and comments about the woman lead me to believe you may have more against her than her using your cream once…my guess is she didn’t see this as some special “diet” food. It’s not like she ate your lunch.
Well, an opportunity came up during a conversation about grocery shopping and I asked her not to use it since it was part of my diet plan. I don’t use the fridge for anything else (I live close enough to go home for lunch) and when I’m not on this diet, I use the furnished Coffee Mate creamer. I just think conflicts over food are awkward because I’m from the south and we feed everything and everybody.
When I said she eats everything that doesn’t eat her first, I was being funny, but it is true. In a way, I am a little jealous of her. She drinks 2 or 3 cans of soft drinks a day and eats cookies (we bake them in the office for customers) and crap all day and never seems to gain weight. I eat nothing good and struggle to maintain. She has started to gain a little lately, which is only fair. haha
Stick to the real cream. That Coffee Mate stuff is chemical crap. 
In fact, if the company is buying Coffee Mate, convince them to switch to buying the real stuff. If you’re baking cookies in the office for customers, might as well give them the good, real stuff, too.
If she had asked you if she could use some to cool down her coffee, what would you have said??
Several years ago, I worked at a place that had a shared kitchen for about 10 employees. The company supplied coffee and the dry stuff, but no half and half. I prefer half&half and won’t use that yucky dry stuff, so I just bought the large container knowing that others would probably use it as well. Again, unless money is tight, we’re only talking about a few dollars a month.
I spent $85 on Amazon for my own small refrigerator for my office to not have to deal with all of the communal office refrigerator issues. Money well spent.
It takes A LOT of cream to cool down a mug of coffee! Betcha Karma will bite her in her newly fattened rear end.
Of course I would have said yes if she had asked, but I don’t want it to be an every day occurrence, mainly because I hate going to the grocery store and don’t want to have to make a special trip for my favorite cream.
Completely agree with @doschicos - Coffeemate is disgusting, but some folks who avoid dairy can prefer that.
One Mini Moo is 0 g carbs and 10 calories. I just checked!
Good luck with the job @musicmom1215 - some small offices can have their quirks, and maybe intensified with being small. Maybe this co-worker was testing how far he/she could push you, or maybe trying to push your buttons? Doesn’t sound so innocent to me. It may just be a person who doesn’t appreciate respectful boundaries.
Too many stories heard about shared office frig situation, including theft of food (someone’s lunch stolen). That really puts a bad feeling over your co-workers.
In our office, we had a lot of people leaving food over days, so the food went bad. Every so often, one of the frig users would say “anything left in the frig after work today is getting cleaned out.” That way people could take what they wanted to save, they had a chance to grab any tupperware etc, and the frig could get the attention it needed. Of course if someone was not at work, would not throw their tupperware away. It worked out fine in our office.
This thread is hysterical. Personally I think you are making a mountain out of a molehill. You have gotten some really great suggestions all of which will most likely solve the situation. Pick one and be done with it – coffee creamer is not something worth ruining a relationship with a colleague over.
Funny, W and I both use cream for 2 cups of coffee each per day and even between us we rarely manage to finish a medium-size carton before it gets all lumpy and close to the expiration date. If you’re trying to lose weight and find yourself finishing all the cream, maybe it might be acting as hidden source of calories?
I am counting carbs, not calories. It works for me. I have lost 38 pounds.
I know this whole thread is trivial. I was a little flustered when it happened and should have waited before posting. Is there a way to delete it?
The issue here is carbs, not calories.
Believe it or not, my late inlaws actually preferred CoffeeMate. I used to buy it specially for them when they visited us. Since they knew I didn’t use it, they appreciated that I made the effort. (Finally, something about me that they appreciated! B-) )
There was a nice older gentleman at one software company where I worked who ALWAYS took the last cup of coffee but left about two tablespoons in the pot. Finally, we put up a sign to the effect that if you take the last cup, please make more, and leaving a few TBS in the pot does not relieve you of this responsibility. When he saw it, he said to us: “I guess this means me.” Which proved that he knew all along. He was an advertising guy whose heyday was probably the Mad Men era, so no doubt he was accustomed to “the girls” taking care of such things. After that he made an effort.