I like the second one a lot but it looks like it may be a tad thin for it being that color. I can see her bra/tank through it which would bother me a ton.
I love the neckline and the sleeves on the second one. It does look a bit sheer in white, so I would probably get it in another color myself. Do they have it in grey, for example?
I prefer the neckline on the second one (high necks on sweaters makes larger chests appear too low) and lilac/lavender is a favorite color of mine. I like the first one as well though as it has narrower sleeves and is a bit shorter. Again that is a personal preference as I'm short waisted and a lot of tops are too long for me.