I have a question about medieval royalty that I have been unable to find out through google and I hope you can help me. Is it true that royalty (and the aristocracy) would often have others dress them? And if so why?

Yes, it is true. Partially, it was an outgrowth of having servants in the first place – they also didn’t cook for themselves, and so on. Partially, it was because the kind of clothing that royals and aristos wore was exceedingly complicated and was much easier to put on and take off with help. 

The opening credits of Hellen Mirren’s Elizabeth I depict this rather well, showing the complicated process of disassembling a court gown.