It's really helpful to teach a stand stay for grooming. I set mine in a stand stay with a handful of his kibble at my knee so I can give him intermittent rewards for holding the stay and I'll release every couple of minutes before I set him back up for more. Mine doesn't mind grooming, so he'll work for kibble. If you find she's very fidgety or doesn't particularly like grooming, you can also give her a higher value reward for holding the stay. Mine gets hot dog bits for holding his down stay while I grind his nails because he absolutely HATES the grinder.
If you're used to grooming her while she's lying down, you could also give her a stuffed Kong and let her work at it while you groom her.