DS is in UT for ME right now. I’ll actually disagree with the reply above–if your daughter truly wants to do ME, and she has other good options, consider them. Do try an appeal to switch before the fall, my DS knows one friend that managed to do it, but it’s far from guaranteed.
Internal transferring is also difficult depending on semester. For perspective, this semester, many students with 4.0s were rejected from both ME/ECE, there was a whole Reddit thread about it, and my DS personally knows many of them. Granted, it is easier depending on the semester/number of open seats, and many kids do manage to transfer, but the uncertainty is definitely something to consider. Kids do change their minds a lot in college, but UT makes it a bit difficult for engineering, honestly.
Furthermore, while physics, gen ed, and (some) math ovelap, ME/ECE actually don’t share basically any ‘engineering’ courses. Many schools require both ME/ECE to take Circuits/Statics, for example, but UT doesn’t, so there is less overlap than most universities. Not a huge deal, though, since the rest transfers.
She can definitely try, just some things to consider. Also know that ECE is also very broad at UT–I’d argue just as much as ME. It offers Computer Engineering, Electrical Engineering (look up the tech core packets, so many options), as well as things like Data Science and Software Engineering in one department–meaning no transfer is required between these subjects.