Catnip is handy too. Sprinkle a bit here and there and she'll probably loosen up a bit. Put some around/on the scratching post.
They are hyper cautious anyway and it'll be even harder if they're feral. Living wild means being afraid a lot. Maybe try putting her food and water bowl closer to your living room so she has to eat around you? Or put an old hoodie or sock near the bowls so she can smell you guys while she's eating but without you being physically close. All about trying to create positive associations for her. She might not eat for a bit but hunger will get the better of her eventually. Try to get her to eat some treats out of your hand too (once she's further along).
Also plenty of toys you can play with together will really help with bonding. Aim for 20 mins of playtime a day. Those wands with string are great, laser pointers, wind up mice, basically anything she needs you to make work but also other stuff she can bat around on her own. She can keep her hunting n pouncing skills sharp too - crucial if she has until now relied on her own wits to find/hunt food. Basically she still needs to feel like an independent woman, there are lots of cat puzzle things you can get that reward play with a treat.
Maybe try one of those plug in scent things, they can help her acclimatise too.
Hope it goes well, keep us posted.