So, several things...
This is Snow's second Bad Game. And it kind of destroyed one of her coping mechanisms.
See, Snow lies a lot in canon; basically she pretends to be a happy, perky person because it's easier than dealing with things. Her friends actually worm their way beneath that, no matter how much she tried to keep them out.
At first, Merry was that way on her own. But, between Badger's pessimism and Razzy's guilt over Merry's first bad game, Merry began to feel like she needed to stay that way to make sure everything was okay. Basically to protect the tinies/newbies on Bunnycorn and her jaded teammates: look confident and happy and badass sorceress. And, well, it was all she could do to keep June calm during the game.
The badass sorceress thing is critical since she pretty much allied herself with Mirror to avoid being defenseless in games; not for herself, but because others would try to protect her. So, having her magic failing to save June was a pretty bad blow, even if it did help Badger not feel like he was in total pain when they had to jab him with needles.
However, her teammates took one look at Snow's 'I totally got this, guys' and pretty much did the 'no, you don't' -- don't try to lie to a lawyer and a detective. So, she'll probably be more honest with them about things, rather than trying to bluff her way through.
On the other hand? Totally going to be ruthless, since she figured out that Monoceros -- well, Badger and Quartz -- can't be. So, Snow takes one step towards being a ruthless evil sorceress. At least Snow's Mom would never care about anyone besides herself, so Snow still has her love for her friends to keep her from going totally off the deep end? On the other hand... well, once she remembers mind magic, there may be problems. Thank goodness for bracers.
She totally gets why she sounded like such a martyr in her message to herself: she probably came to Sabra to protect her friends from something, and her friends probably think 'amnesia murdercave' is a terrible idea.