Food, specifically wet food works the best. Get a large table spoon and try feeding her off of it. Slowly bring the spoon closer to you as she gets used to eating that way. Stinky canned fish, like mackerel may work too. Let her hear you opening that cat too!
Make pleasing sounds. Cats usually respond to female voices better, so your mother obviously has that advantage. Try "brrr"ing at the cat and imitating some of the noises the cat makes. Just remember that low and long sounds with the "ow" on them usually mean "back off" or "I'm not happy". Light "meeh" sounds work well.
Never use the "ssshh" noise as it sounds a bit like a hiss.
I think the Feliway may have little spray bottles too? (does it?) If so a little of that sprayed on pants around shin level - where a pet cat would normally rub may help.
If someone else can verify whether that might help?