If I hear of someone called Jackie or Michelle I assume they're probably in their 50s or 60s as those names were massively popular for about 20 years in the 60s/70s and then sort of disappeared.
Likewise a Wendy signifies an elderly woman, a Gemma is usually in their 30s or early 40s.
On the other hand an Alice, Lucy, Elizabeth or Catherine could be any age.
In 2050 I suspect the names Sophie, Ella and Ava will immediately conjure up a middle aged woman, while Jessica, Amy and Becky will be elderly grandmothers.