Elli,
I just want to say that you are a wonderful young woman with a very warm heart. What you are doing is a great thing and I am sure the children will appreciate this. My kids know what it is like to lose a parent also, although they were not as young as you but it is still a very hard thing to deal with. The fact that someone cares enough to give them a little something to take their mind off of the tough stuff and show that people care is awesome.
Keep up your wonderful attitude.