Pressure to switch dayhomes to grandma

[1sttimer]

I thought this would be the best section to post my question in.

My DD is with a great dayhome now through an agency, partially subsidized. I'm a FT student until 2018. My MIL is in the process of starting a day home. My daughter has a great relationship with grandma but I have no desire to have her care for DD full time for various reasons.

I'm positive she will suggest I switch over to her when she's ready and I'm preparing my case so to speak. Anyone heard of this kind of arrangement? I'm kind of hoping it won't be allowed just to avoid any drama. We do not live in the same house and I couldn't afford care without the subsidy.