BAM! In the pussy!
That statement alone means she digs you, the smiley face at the end clinches it.
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If she weren't into you, she wouldn't have chatted with you for 7 hours straight on the first interaction.
I sure wouldn't to some rando if I thought she were ugly or a weirdo.
Usually it's the guy's job to initiate the "hangout" offer, even if the girl wants to too.
When a girl throws the Q herself, she is DTF (just kidding, but not really)
She asked the mutual friend to tag along on the *first date* so it isn't awkward and so you both have a buffer in case things don't turn out as well as you two hope. The first date with the third wheel is the one where both of you get a better, in-person feel for the other before proceeding.
Don't fuck this up or she will run away like a wild Suicune.
Too freaky or nerdy and she's gone. Too pansy and you're going to be hearing her stories of how to get another guy.
Besides, first dates are always the most casual, having a friend between you makes things more spontaneous, easy, and well, casual. The friend is there to throw ideas an ensure smooth flow, reducing awkward silences and such.
I would be more uneasy if a girl wanted 1-on-1 at the get-go, as that would imply she is a whore/cheater/easy/psycho/clingy. Though if you just want to release the pressure valve, a one night stand is standard. (okay, this part was off-topic)