Welcome to EBN. I am sure that many of your questions can be answered here. At the very least, alternatives and suggestions can be offered. The people here are wonderful and extremely helpful. I am not knowledgeable about hair loss but have read a few posts stating hair loss on the sides can point to alopecia. You may want to bring that up with your vet and get their input.
Be sure to post lots of pictures of Penelope! We love to admire each other's pups so expect that many will ask! lol We look forward to hearing stories about her and seeing her pretty face.