Unfortunately, they don't look like they are because I'm too lazy to draw the rest of them XD so yes, I slight view on how the girls might look as adults...I guess Alice changed more than Izzy. Alice isn't so shy anymore, she's as mature as a certain love interest of hers became, she pretty much ignores Izzy's teasing(which doesn't happen much anymore)
not to mention the fact she got sexier ROFL *slapped with wet frog* and her hair is longer(about halfway down to her back, maybe a bit longer)
As for Izzy, she's much more mature too, she barely picks on Alice, the dyed part of her hair is longer, she has an awesome pair of goggles XD but she sometimes backsasses(did I spell that right?) people when they get on her nerves, her emotions are a little easier to control(Alice's are too, but she's as beserk as Izzy was in her teens whe she goes into her beserk state, which is bad because Izzy was so beserk she caused a huge 'car crash' just by using some vines to throw cars off the road)
Also, Alice could now manipulate the water in people's blood, but she doesn't practice it much because she's worried that she'll kill someone...and Izzy could manipulate rocks/stones/earth now...