I always had the feeling they were originally setting up Tina McGee to be Harry's E-2 wife based on Harry's reactions whenever he heard her name or saw her in S2. There was even a deleted scene with Harry & Jesse in their room at Star Labs looking at a drawing of a woman with Harry that looked a lot like Tina McGee. Not to mention Tina and Jesse could pass as mother & daughter. I'm not sure what happen, if that was the case, since at the end of S2 they did a fan shout out for the original Barry Allen/Henry, John Welsey Shipp, and Tina McGee for about 5 minutes before they killed him.
Amanda Pays, Tina McGee, has not returned to the show since the end of S2. I'm not sure if she didn't want to continue on or if the potential plot line of, maybe, Harry and Tine hooking up turned her off. I know Amanda Pays had pretty much given up acting to raise her 4 boys, whom should all be adults now, before returning on the Flash . She is also very devoted to her husband, Corbin Bersen, and they have been busy promoting a book they wrote on home improvements. Hopefully we will see Tina McGee return again at some point, but with each passing season, I'm starting to doubt it.
I'm wondering if the Mystery Girl could be the Speedster girl Jay Garrick is training.
On a side note, has anyone had a "vibe" about Harry not being quite right this season? I especially noted near the beginning of the episode, before the bomb, where everyone was discussing DeVoe, Cisco said "just like Thawne," and Harry repeated "just like Thawne," quietly to himself. No one else on the team seem to pay any attention to his comment. A couple people on the boards have noted that Harry's been doing that thing with his glasses again too. It could also explain the Mystery Girl's reaction when she met Harry at Jitter's, especially if she is Barry's daughter/granddaughter. Although, someone pointed out Harry was having trouble remaining with Barry in the Speed Force thing he created and Cisco should have been able to pick up if he was different. So I guess it's doubtful. Then again, they have never explained how Harry's wife died and we know that Thawne was able to feel Wells emotions for Tess on E-1 when he took over his body, so who knows.
One more thing, it seems like they are trying to hook up Harry and Caitlin, I hope that's not the case. I'd rather see both of them with people closer to their ages.