I think you should separate the two offenses. She lied to cover her ****, not to manipulate the situation. I would focus mainly on the stealing, but I'd also let her know that she is in MORE trouble for lying about it than she would have been if she'd have admitted it in the first place.
Also, I wouldn't let her get away with not telling you who the other child is. She's 8, she shouldn't get to run the show. If it were one of my DD's, they would be grounded until they produced a name. And then I would likely call the other parent- not to blame their kid, because your DD made her own decision to steal, but to give them a heads up of "fyi, my DD did this and told us the two of them had spoken about it, so you might want to talk to your DD...and hide your purse...lololol!" Kind of a "haha, kids!" heads up.
I understand kids lying to cover their butts. That to me is normal, age 5-8 behavior. Stealing from your parents should not be tolerated. I'd really be more pissed about the fact that she stole from ME, who provides her with everything her little heart desires, because it's such a slap in the face to you. It's different from swiping a friends lip gloss because she is impulsive & wanted a lip gloss. She's taken money from you before & gotten away with it, so she felt she could do it again. I'm with TON on this. We're trying so hard to nip certain behaviors NOW at age 6 & 7 so we're not dealing with nightmare children in 10 years. We've been doing a lot of writing lately. :lol:
Maybe your DD would benefit from seeing how little others have to appreciate how much she has.