Am a guy but put the question to my partner. She's in her mid 30's and digs solo bar trips where she can either engage with strangers or just hang out and read a book while not being bothered. We both had pretty much the same short list immediately come to mind: Deluxe, Trina's Starlite Lounge, & Highland Kitchen. Back Bar is great but can be a little cramped. I would also toss the Behan in JP into the mix while she would suggest The Abbey in Cambridge.