no idea of the exact stat/levels needed, but at least in DMM aigis you can somewhat boost her attack easily (Uzume buff, aria buff, dancer buff etc.)

@buttlover: there ARE players who can be that hardcore (in particular jp players). nobody said you had to do the same. nonetheless, it IS good to have her AW'd, and you can use her to farm LCB1 for silver fairies for powerleveling AW fodder. according to exkale, 4 silver fairies + 4 lvl 25 bronze (or was that even higher level?) from the higher tier maps (currently not existing in nutaku version) can power a silver straight to lvl 30 for cc'ing.

nonetheless, I myself didn't AW betty because I'm too lazy to mass farm pastoral gate. especially when I'm not lacking gold yet anyway.