Accommodation In Exchange Light Baby Sitting

I am looking to find a nice young student or anyone with the need of accommodation free of charge in exchange of some light baby sitting for my twins. I am a single mum and needs some help however since kids are in child care all day and I have a lot of free time I need only help some evenings when my roommate would be home anyhow so that I can go out for dinner or grocery without having to call a nanny, also some help during weekends but everything is flexible I do not have a precise schedule, I also need a flexible roommate with whom to plan week by week on the availability... thank you
Preferably european your female