I'm a member at PR (patternreview.com) and believe me-it's far more extensive than KH-not meaning anything bad about KH by any means!! Hope no one takes it that way-I LOVE KH! Its what helped teach me to knit
But there are thousands upon thousand of reviews, of patterns, sewing machines/sergers, books, techniques, notions and the message boards have everything under the sun about sewing she could want to ask. I am sure she would LOVE it and it would help her expand very quickly her sewing abilities. I've always found everyone to be friendly and helpful, as well.
good luck to your sister!