It's my experience that at 6 months of age it's already impossible to socialize a feral cat. We have a semi-feral who lives in the house with us. We brought her in at the age of five weeks, and still she never lets us near. You have to get them very, very young and spend a lot of time holding them, talking to them, playing with them to get them socialized. Even then it's not a sure thing. I'm not saying it's impossible, but it may be easier on your friend if she, so sorry to say it, gives up.
Here's what I recommend.
Borrow a couple of humane traps from the local humane society. If they don't have them, get in touch with Alley Cat Allies or Best Friends. Any of these can put you in touch with someone who can lend traps. Read up on how to use the traps (Alley Cat Allies is the best site for such info).
Alley Cat Allies
http://www.alleycat.org/NetCommunity/Page.aspx?pid=191&srcid=-2Best Friends
http://www.bestfriends.org/Trap the cats, take them to be treated for fleas, get them their shots, have them fixed* if they're not already --
Then turn them loose outside and care for them as outdoor cats.
It may sound wrong. It's a wrenching hard thing to do, but this is my best advice. Remember: they are cats, and they are wild cats. Their instincts are geared to outdoor, wild life. They will survive well until they realize they can come to your friend's house for food & water, and hopefully she can set up some simple outdoor shelter during winter.
I don't want to trump anyone else's advice. This is what I would do.
Household flea treatments are available. Google is your friend.
* Read on ACA about ear tipping. If the tip of the cat's ear is cut off (done during sterilization), it's a signal to whoever that this cat is fixed. You can educate people about this -- "hey, don't worry about that cat, It's fixed and I'm caring for it, you can tell by the ear."