[Quintease]

The first time I dated someone trans, I had a real problem acknowledging 'she' was a 'he'. I was a lesbian goddamnit! And lesbians didn't date men.
But I couldn't help myself, he was so amazing that I couldn't stay away.
It didn't help that at the time he was going through a period of discovery himself, so didn't have the confidence to fully come out.

I barely knew anything about trans, so it was invaluable to me that he took the time to talk everything through with me, to answer all of my questions, lend me books and even show me a video. It was an eye-opener which would never have happened had he been the sort to take my ignorance personally.

The second time I dated someone trans I thought I was down with the kids, I thought I knew. Of course I realised how ridiculous that was about a week later, particularly when I remembered that I was a lesbian.
Luckily my husband was happy to talk to me about anything and everything and even argue with me on occasion when our cultures clashed.

1. How important is the full understanding of trans-gender mentality and needs to be a complete partner to someone who is trans?

It's not important. What's important is she care about her partner and try to meet his needs and he do the same. In time she'll either learn on the job or he will terminate the relationship.

I find she bounces back and forth with her pronouns for him as well. Referring to him more as 'her or she' than 'him or he'. This tells me she really doesn't understand, or take this seriously.

She's probably trying to square up the two realities. If she's had a straight life up till now, none of this will fit the world she's been living in for most of her life. In time everything will start to make sense or else he'll get fed up with her and leave.

She leans on me, knowing my history as well, but I find myself at a loss to really 'knock' the information into her, to make her understand him as well as I understand my Daddy.

The two of you have different partners, different relationships. Understanding your relationship isn't necessarily going to help her with her own.

The second part of my issue, is that her lover, is highly emotional, and takes a lot of things really really personal, that aren't meant to be.

If he is not able to be a patience and tolerant educator, than she is not going to learn. Simples. He either needs to grow up or give up. Her 'manipulation' is probably the only way she knows how to defuse the situation. He feels bad, she gets a break.