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Hi. Welcome. My name is***** Thank you for your question. Thank you for giving this girl a good home. Has she ever been to your vet? How long have you had her? In a situation like this, there honestly isn't anything that is going to be given as an over the counter that will sedate her enough to allow you to do this. As far as at home with a cat like her, some owners can "sneak" up on them when they are sleeping and do a nail or two at a time and over the course of a few days be able to get them all. In her situation, if she's never been to the vet, it would be a good idea to have her seen by them so they can check her over and to get her caught up on vaccines. While there, they can easily trim her nails.
That is great that she's been to your vet and had that check up and flea preventative. They hopefully gave her the overall clean bill of health. As far as trimming those nails again, at home maybe doing one or two at a time when she's resting / sleeping is the best thing that you can do there. If you have a friend / relative that can come over and help hold her, this is actually a pretty common way to have it done. With my cats, my wife and eye tag team it to get it done. One holding and the other trimming. My own cats won't let me do it by myself.