Sorry for answering like this 2mahnas and tchernobog, but I wanted to make sure the image was view-able. Anyway, RD’s wings are actually kinda small; short and narrow for speed purposes. If you wanna talk impressive wingspan, it’d be better to look to Fluttershy, who has the longest wings of the Mane 6. Twilight’s wings, when she still had them, weren’t as long but they’re the widest. She misses them dearly.
Just a really quick doodle to show off the wingspans, hence the lack of manes and very simplistic lines. Also, I’ll be doing a height chart of the Goddess!AU Mane 6 soonish, but for reference here: Twilight’s probably 5′11 in this AU, Shy’s 5′9 but she sometimes hunches to seem smaller that what she really is. And if course, Rainbow Dash’s 5′4, the short gal.
That said, to answer your immediate questions: RD’s wings are large enough to give Applejack a wing hug. They’re also very strong, so if RD were to pick AJ up and fly, she’d be able to fly without much of a problem, so instead of a glider Rainbow would actually be able to carry Applejack. Her size undermines the strength she carries in her body. o3o