HATE to say it bc I shipp Lee and tenten but I don't think so..we are pretty far into the manga and esp the anime to not get confirmation either way if tenten is metals mother or not. The most telling evidence is the anime and the current chunin exams, we had tenten overseeing the early test with the whole batch of genin and we have tenten and metal only feet away from each other and no quick moment of acknowledgment at all....in most cases if a parent is close or in this case a exam giver we would had the child mention it in some fashion..example inojin and his dad sai in the exams, you can't say it makes sense that in the same situation metal doesn't acknowledgment his persumed mother at all. As much as I want it to be true, I don't think it is sadly.