She Is ADORABLE and looks WAY more yorkie - I can't see Pom in her but I'll take your word for that - she is adorable and so pretty -
On Grooming -HERE is a good link I had saved JUST for this kind of post
http://www.ytca.org/grooming_clips1.html
You can take it slow with blunt nose sizzors so you don't take chances - has she ever BEEN groomed ? If she's scared of it you may want to get someone to help you OR take a chance and see if you can find someone who specializes in skittish/scrared (of the groomer) doggies - I have one near me that vets send the dogs that don't like being groomed - He's SUSPOSED to be very gentle ...
She has a beautiful coat - you could probably trim her up yourself - Get a Wahl trimmer if you need it for her little butt and under her feet -
OR you can sizzor cut those areas also...Congratulations on your baby !