Ren takes it well.
Actually Ren takes it with five minutes of bewilderment, wants to pull May's antlers, needs to see the witch outfit go on and off a couple times, and passes a hula hoop May didn't even know they owned around May's levitating self, and then takes it well. She's very excited, wants to know if she can be a witch too, hares off to look for the shop entrance and can't find it, and decides to live vicariously through May's witchhood.
Charlie's more complicated to tell: even at 85 miles per hour on her broomstick, up high enough not to be observed should her cloak flap, May would take a whole day - complete with not sleeping - to get there. May winds up experimenting with her picture-entering power and determines that while a print of Starry Night from Amazon won't work, one she personally takes to the copy shop and reproduces does. (She's apparently not the first wulong to choose specifically Starry Night as a transit mechanism; there's a candy wrapper and some property damage in there.) So there's one in May's bedroom on the wall, now, and one rolled up in her luggage for school, and one Fedexed to Charlie, and then he has to be pestered to mount it in her bedroom in his house without understanding why this is so time sensitive, and when he's done it, and tells her so, out she pops. Then he also takes it pretty well, in a way that might be mistaken for shell-shock at a distance. For her "bag of holding" she's using an art class landscape she won third place in the school art show for sophomore year; she gives most of her clothes to Goodwill and drags her emptied dresser into the scene so she has a place to put things that isn't just lying around on the grass.
Arcadia figures something out with her withdrawal from high school, and May tells anyone who might note her absence that she is going to university early. Which is true.
And when her residence is available, she packs up her Starry Night and her clothes (not very many clothes, but she might ever want to wear her remaining civvies or a bathing suit or a bathrobe or a raincoat or something, and it makes it a little easier to keep track of her invisible servitors if she puts them in T-shirts) and her crayon drawings from Ren's hoard and her iPod and a couple knicknacks she picked up during her trip to Goodwill for seeming mana-y, and she stuffs everything in her landscape and her landscape in her pocket and takes the bus to the portal network.