Well I'm assuming that she hasn't been desensitized yet.. so just work on rubbing, patting, poking, tugging on her mane, brushing her everywhere (safely) not just focusing on her legs.
I wouldn't try to pick out her feet until she trusts you a little bit better.. And just work on getting her comfortable in her own skin. When you've desensitized her with yourself.. then you can start focusing on picking up those feet. I'd work on teaching her to rock her weight back and forwards and side-to-side depending on which foot she will need to take pressure away from. Make sure she understands pressure release.
Once she can comfortably rock her weight in any given direction, work on leaning against her until she rocks that weight and as soon as she does, release (stop leaning on her.) When she's got that down, start asking her to pick a front hoof a little (for a second) and then YOU slowly guide it back down. Don't let her take it from you.. always put it down before she reacts. Then slowly work on having it up for longer periods.. 1 second, 5 seconds, 8 seconds, 10 seconds, 12 seconds... etc.
Once she's comfortable with you picking it up and setting it down before any fighting ensues, MOVE ONTO SOMETHING ELSE. If you focus too much on one thing, it can be too much for them to process. Keep the sessions short.. to the point, and make it a daily affair (or when you can do it.) Be consistent but constantly build a little bit each time.
Once she can pick up her hooves.. then work on picking one foot and you can take your time with it. If she tries to take the hoof from you, don't let her! Tell her easy.. she could be trying to move other feet around to get her balance. But I always like to put it down before they resist and just do it for a little bit longer the next time.
If you do too much at once and they resist and throw a fit, you'll have to start pretty darn close to square one. Better to take your time and make it good for both parties than to rough it just because they need to do what you say.
Does that make sense?
Then you can start picking them up and cleaning as per usual. If there is any resistance.. don't give in. EVER! Either get out on a good note or stick it out and WIN.
Hope I helped.
I'll add.. some people use ropes to pick up their horse's hooves if they are resisting.. it's worth looking into. Just make sure to desensitize the horse to the rope.
Hope it works out!
"Strength is the ability to use a muscle without tension"