What kind of resistance does she put up ? Squirmming or pulling her foot away ? Does she show teeth ? Have you tried putting her on her back and cradling her between your legs ? Or if you are doing that maybe on her side ? Or maybe while she standing ? I know you want to be able to do it so just do it. That's what happens when you take her to the vet/groomer...they just do it even if it's a struggle. I believe you can handle /treat her feet for a week or 2 then just trim 1 nail at a time each night after treating/handling and after 20 days she will be more acustomed to it...just throwing some ideas out there. Keep it short and sweet but you must win !!
My perference is to have her on her back between my legs, and when she was cooperating, that's what we always did. Now she pulls away, won't lay on her back, thrashes, and tries to run away. it's quite violent, but she doesn't show her teeth or bark; she just tries to get away. I've tried letting her stand, having her sit, every possible position, but as soon as I hold her paw and she sees the clippers, the struggle begins. I can't do even one nail without worry about cutting too deep.
The groomer/vet has the advantage of not being me, I think.
I couldn't get near her with it whether it was turned on or off. I am hoping that when she gets older, I can try again and perhaps be successful. I really think the Dremel does the best job, but not when it turns the dog into a whirling dervish!