I think this name is cute. However, it’s difficult to pronounce so I would probably use the name Avalyn instead because I feel like it's spelled how it’s pronounced. Maybe a good middle name option though.
"AV-ə-lien" and "AV-ə-leen" are given as pronunciations for both Avaline and Aveline. However, like with Evaline and Eveline, as well as Adaline and Adeline, I perceive the variants with the "a" in the middle having the "lien" ending, while the "e" variants have the "leen" ending.