I thought of that too. If Warp knew there was a psychic in the group, she would offer to have her mind read.
But once it's established that she's for real, the end of the universe kind of makes everything else pale in comparison and we'd look kind of silly for still worrying about a casino robbery (plus I have a feeling the casino robbery is actually the first battle). I'm worried about driving the plot off the rails, creating a lot of extra work for Arthur, or giving Warp too much of the splotlight by having her be the one to warn everyone of the big bad.
So I think it'd be better for Warp not to be taken seriously, at least at first, at least not by the majority of the characters. She might resist your mind reading (Legacy's an unknown quantity, so she wouldn't trust him not to mess with something else in there). If you overpower her anyway, there might be concerns about whether the memory is real or implanted. After all, Warp has never displayed the ability to turn back time by the amount she did. Or Legacy might feel unwilling to trust the memory anyway; he has, after all, seen humanity's glorious future.
I guess this all depends on what Arthur and the rest of you want to do.