I love Vida, Levi is alright, but Livingston? Poor child, not only is it not a very pretty name in my opinion, it doesn't fit the names of his elder siblings either. That, right there, is bad naming on a very high level.
I sort of like it.
Actually I like it, though I don't think I'd have the guts to use Livingston myself unless perhaps it was a family surname (which it might be for this couple, who knows?) I agree it doesn't match his siblings' names well, especially when you see it next to Levi, but taken by itself I like it. It could sound scholarly (Dr. Livingstone, anyone?), and it fits the surname trend while being quite unusual. And a couple years back I thought the name Livingston/Livingstone (containing the words "living stone") could be a cool reference to 1 Peter 2. And hey, I also love Livingstone daisies.
Levi & Vida blur together for me personally more so than Levi & Livingston do. Like some have said, I don't see Livingston as the best fit with the siblings' names, but they do all have the "vi" syllable & I find their love-of-life thing is endearing. :) I bet the baby'll get a cute nickname, and me, I'd always take unusual Livingston over well-established Logan, Landon, etc.