Texas standerd child support is I think 20%. My X pays less. Half of all medical (birthing encluded) and all insurance.
If your grand daughter is on your plan then he either has to provide it or pay you the extra for having her on the plan.
As far as I know in Texas (my home state) there is no special rule for enfants. If you live 100 miles or less then he gets a few hours on thursdays and every 1st, 3rd and 5th weekend (starting on friday). Plus 30 days in the summer. Because your granddaughter is pre-school then it will be based on the school district she lives in.
Forgot all of Texas school start and end at the same time now.
Oh and good for your daughter going over there but with the gas prices like they are he needs to be helping. He should be paying gas or coming over there some.
Sorry if I keep adding but I keep thinking of things. Othes on the forum will say a baby that a baby needs more time with dad then that but for shorter periods. correct me if I'm wrong "Jada". I'm starting to see the point to this.