everyone gave you great input already, so im just going to make one recommendation for when you go to pick one out, if ella is very small, try a cat harness because they actually fit a little better. FastEddie recommended this to me because Sirius' harness was too big even though it was THE smallest size they carried for dogs.
Alaskayorkie- i think for training purposes, using a collar ups the sucess by like 400%- i use a harness when i walk Siri, but for training a few times a week we use the collar. its not like im tugging at him or anything, so i dont think its harming him. and once hes trained, i hope to not need to use it, so if someone gives ya crap, send em my way too
