Disclaimer: Before consuming any plant identified via an Internet community, do your own research and confirm the id.
Based on the photos alone (scent is a huge factor when identifying herbs), I would classify this as Satureja montana, winter savory.
The overall habit is similar to thyme, but it’s larger, more vigorous and the leaves are thinner, albeit a bit longer and less pointy than thyme.
Winter savory (as opposed to the closely related milder summer savory1) is a perennial plant with a bitterness underlying the overall scent. Dried it can easily be confused with thyme, but the scent is quite different, yet distinctive.
1 Considering that summer savory is not frost-hardy and an annual, I would expect your mom to remember sowing or planting it specifically. Perennials tend to be “just there” in my experience, having had to remind my mom now and then what herb grows where. (Maybe plant tags would be a good Christmas gift...)