I seriously love [name_f]Lila[/name_f] and I’ve had the same concerns as you have as to whether it’s too trendy. Inspired by this article 2013 Playground Analysis: How combined spellings change the rankings | Nameberry , I went through the most recent SSA list to find all of the spellings of [name_f]Lila[/name_f] and add up their usage. I found:
[name_f]Lyla[/name_f] was used on 2069 girls (#153)
[name_f]Lila[/name_f] was used on 1681 girls (#192)
[name_f]Lilah[/name_f] was used on 1039 girls (#307)
[name_f]Lylah[/name_f] was used on 439 girls (#635)
Total = 5228, which puts it at #36 between [name_f]Anna[/name_f] and [name_f]Aaliyah[/name_f]
So that’s a lot higher than #192. And like you said, there are lots of Lilys, Laylas, Lolas, Violets, [name_m]Milas[/name_m] and Islas around, and [name_f]Lila[/name_f] repeats a lot of their sounds, so even if you’re not actually hearing it, there’s a good chance you’re hearing something similar.
That said, the name at #36 on the list still only represented 0.2721% of the girls born that year, which would mean two or three girls out of 1000 would have been given that name. So unless you happen to live in an area with lots of [name_f]Lilas[/name_f] running around, it’s still not likely to be super common. And #36 is still lower than [name_f]Audrey[/name_f] (#32) and not drastically higher than [name_f]Claire[/name_f] (#49).
I also looked at [name_f]Lila[/name_f]'s popularity over the last 100 years, and it’s seen increasing use since 1998, before which it wasn’t in the top 1000 for several years, and before that it was low on the list. It was last around its current level of popularity in the 1920s, and the last time it was more popular than now was in 1930, at #170. The [name_f]Lyla[/name_f] spelling has never been nearly as popular as it is now, and [name_f]Lylah[/name_f] has only been on the list since 2009, and [name_f]Lilah[/name_f] since 2006. So [name_f]Lila[/name_f] feels much more like a vintage/classic choice to me than any of the other spellings, which in itself lowers the trendiness factor [name_f]IMO[/name_f].
That said, and this is biased by my love of the name and desperate hope that it isn’t too trendy, it’s a name I’ve heard for years in books or TV but have never encountered in real life. I do find it really versatile and I can see it aging well. I concede that it’s possible that people 30 years from now will associate [name_f]Lila[/name_f] with girls born around now, but to what extent I don’t know.