I can read lesbians like a book.
I had a friend (lesbian, and I was presenting as female) tell me she had a boob job, and describe in great deal how they felt and all that, lol. but she wasn't interested in me whatsoever. She only liked femmey femmes, that was an undeniable fact.
The touching is another thing that probably means nothing in that context...I've known girls who act like that with each other too. Presumably not into each other. It sounds like your wife is just really enjoying it, enjoying being "one of the girls" (at least one of those types of girls, lol).
Honestly, it doesn't sound romantic or sexual to me. At all. If I'm wrong, I'd be very surprised.