Tom: WTB Carthatic reunion.
Mara: Sorry, not for sale. Sold out.
Mara is in an odd place. All Miharu missions carried some importance and gravitas. They had stiff odds. When things went bad, she usually lost her legs. At the worst, she'd actually die and be respawned. Unfun, some people would not like it, but life would move on.
So, Mara takes a backup before the mission.
And wakes up years later with sisters years older than her (when she was actually the eldest), acclimated to life on the homeworld and having moved beyond existance on the ship. Everyone is desperately happy to see her, warm with praises of what she supposedly did that was so heroic.
But the Mara that's alive now has never done any of that heroic stuff that other person did. While it's flattering to know she might have the spine to come through in such situations, it wasn't an effort she herself had to live through. It's like a stranger had lived part of her life and done extraordinary things she can't take credit for. Mara was a bit grandstanding, mischievious and irreverent - and all that sudden shift into that heroic figure that's carved in bold letters on the Miharu Shrine just feels at odd with her.
And of course, then, there's the counseling help she's received. And she kind of resents it - she's not mentally ill, all she did was wake up and everyone else became different! Everyone seems so focused on their personnal loss, on the heroic figure Mara became, that they cannot seem to see her as she is today.
Oh, she did miss the other members of the Miharu crew, and she did like the idea of being a new and better ship - what she had in some ways wished she could be for the people she wanted to support - but she wasn't looking forward to the reunion. It'd be yet another instance of people getting all weepy, of people being relieved to be salved of a loss (a loss she somehow managed to make more poignant by being a good spokesperson when it mattered - who would have thought?) and focusing on their personnal pain rather than on her.
Mara isn't blinded to Tom's feelings and she doesn't want to come across as cavalier with it, but she is truly sick of getting this reaction. She's trying to care, she's not succeeding, so instead she tries to brusquely show her point of view in a not entirely eloquent "look at me, dammit!" manner between the lines.