I would consider the kindergarten child a half day so I (personally) would take whatever your daily full day rate is and divide in half.

as for the after school child -- if you are making a special trip out to the school to pick up the child and also providing some sort of snack then I would charge $15.

after school usually ranges anywhere between $10 - $20 in my area depending.

Good luck.

You could also try looking up other provider's ads in your area to see what rates they have and sort of price yourself around that.