Willow

[Quercus3]

How popular is it now? I loved it for years but I'm hearing it more and more, and worry it could be easily dated to this time in the future.

Also like Robyn and Helena, middle name would be Elizabeth or Abigail.

Why are you worried about the name you love being thought dated some time in the future ? That's the case for almost any name. Are you on some magic level hoping your daughter will somehow not grow older if you pick exactly the right name ? Just choose the name you love now.
Willow is a beautiful name.

Willow is just outside the top 50 I think so definitely getting more popular but it's not everywhere. I do think it will be dated to this time just because it's never been used as a name much before but it could still be popular in 30 years and therefore not be as dated if you see what I mean. It's hard to predict though and I think it just comes down to whether you love Willow enough to risk it.

Helena is lovely though, and very hard to pin down a time frame on it so I'd go for that if a name being dated really worries you.