@thumper1 No not at all. The original post talked about them being dual income but a coworker's family was single income because the wife was a SAHM. OP expressed frustration because she chose to be a SAHM instead of earning an income. I am simply saying who are we to judge someone else's circumstances. I was addressing OP.
There are many valid reasons one decides to be a stay at home parent. Each family has their own priorities and values. What I am saying is they don't owe justification for their choices to anybody.
Choosing an expensive school is a choice not a requirement. Some people would rather chase merit aid and others don't want to take on any debt. Others choose a school based on prestige and ranking and are willing to take on the costs. OP is discussing applying to a school that maybe above their budget and needs to assess what their priorities are in regards to school choice
What another family is doing or if someone chooses to be a SAHM is none of your concern. That is their family decision.
Analyze the risks of applying ED and determine if you are willing to take those risks based on how much you would be able to pay. Keep in mind the tuition will increase every year. You don't want to be in a situation where the child attends the first year and is forced to transfer because you can no longer afford to pay tuition at the school.
Either you have already set aside funds for college to pay for the four years or you are dependent on future income to pay the attendance costs. One thing to consider is if you have younger children who will be attending college in the future. You don't want to use all your savings for one child and not have anything left for the next one. Also there is likely a difference in what you can pay and what you are willing to pay. Determine what that amount is and if you feel this college would be in that range and it is your child's first choice without a doubt then apply. If later you decide to decline the offer realize that you will be applying to other schools Regular Decision where admission maybe more difficult.
Are you doing poorly in your classes? If so start going to office hours and go for tutoring. You have to put in the effort if you want good grades. In your other post you ask is it ok to have between a 2.0 and 3.0 gpa. Once you start with a low gpa it is very hard to recover from that and if you need to go to grad school in the future you will have difficulty getting admitted.