Gwen, if your MIL is going into respite care home while you are away on holiday, think of it as her going away on HER holiday! A good care home is like a hotel! They are waited on hand and foot, meals are all provided, and there is entertainment laid on every afternoon. There is company and activities and really, it is like she is on holiday as well. Good care home staff are lovely! The ones at all three of the care homes my MIL has been in (as her dementia worsened) have ALL been lovely. They 'cosset' her and are always 'on call'.
Of course it's natural your MIL will feel a little apprehensive, but I'm wondering whether you can time her respite period to start a little before your own, so you can help her 'settle in' that first day at least??
Forgive me if I've got hold of the wrong end of the stick and it's not her going into a home while you are away.
As for yourself, enjoy, please, this well deserved break.