In theory, yes. It’s a deemed gift.
The gift is staying there rent-free, so your starting point is the market rent for such a property.
But then you correctly highlight what’s known as a “caretaker discount”, i.e. the benefit to you and your mother of not having the property idle. That’s typically around 25% of the market rent.
Then there the €3,000 per person annual gift tax exemption.
But in reality, unless we’re talking about Ailesbury Road here, Revenue probably wouldn’t be bothered with this sort of stuff.