I think
Rune would work fine in the US prn-wise. The fact that it rhymes with "loon" however, does not work it its favor...Looney Runey,
Rune the Loon come to mind and that's without trying. :o) I do love the way it sounds, though. I think that it *could* work, depending on the area where you live and the parents'/parent's and child's personalities.
Rune and
Willow make an awesome sibset, imo -
Rune and
Mira, not so much and
Rune and
Ayla are just way too different stylistically (I think, anyway) to be used as sibs.
That being said,
Draven and
Ayla sound cool together, as well as
Draven and
Willow.
Mira is so sweet-sounding, though, that many of your favorite boys' names just seem to over-power it, Taj, Viven, and
Hugh being exceptions.
Ayla goes especially well with Bodhi, Hawthorn, Kyan, and Wolfstan.
Willow pairs best with
Asher, Hawthorn,
Stellan, and
Dominic.