If you do end up injecting her it's not that stressful. At least it wasn't for Grim. The best way I found was to sit on the floor with him where he was comfortable and give him lots of nose rubs and cuddles. Then I would get someone to take over giving him cuddle and while he was nice and relaxed just quickly pull up the scruff and inject him. Followed my more cuddles and bread.
Bread also seems to be a good one for hiding medicine in as it absorbs it nicely. I've also heard of a few people giving panacur (sp?) between two dandelion leaves, like a sandwich. If you or her get too stressed doing it one way, sit back and take a deep breath, then try and think of another way of doing it. Or come and ask us. It must be very horrible for both of you, but remember not only are we all here for you but there's bound to be some of us who have been in your exact situation so we'll be happy to advise.