Hi Mia,
Where are you based?
There are usually lots of activities such as Jo Jingles music classes, baby swimming, baby yoga, baby massage and coffee mornings in shopping centres and community centres.
Jo Jingles have an ad on here, (see on your right, its yellow & red) you can see a list of their Dublin classes on that, they are a good activity for a 15 month old.
Waterbabies do swimming and I think there is still a parent & baby swim at National aquatic centre.
There is a weekly get together in Ballyboughal, Co Dublin and another one in PJ’s play centre in Balbriggan – are they close to you?