In terms of pacing and adding additional reach schools, I’d pay careful attention to the essay prompts. Below is an excerpt of my general advice on some pragmatics of applying to a large number of colleges.
Some schools, like U. of Chicago, have very individualized writing prompts that won’t be like any other school’s. So adding an application to U. of Chicago (which is not on your D’s list and I’m not suggesting it should be) would be a lot of extra work, whereas a similarly rejective school that has prompts with more essay crossover might be very little work.
Additionally in creating any college list, I would pay very careful attention to my kid’s mental makeup. For some kids, rejection is like a fuel that makes them want to be even more amazing wherever they land. For kids like that, it can be fine to have a number of reaches where rejection is probable (like it is at any school with a sub-20% acceptance rate). But for other kids, rejection can be a big emotional and mental blow, and receiving a number of them near the end of the timeline when schools make their decisions can be a lot to handle. It can also influence their perception of the schools that they’ve already been accepted to (as in, those other options can’t be that good if they accepted me when all these other schools didn’t). So I would never have more reaches on my list than I think my kid can healthily handle a rejection from (and also realizing that targets can also result in rejections…targets are NOT safeties).