Tough decisions

For my two penneth....

Both parents have plenty of time to find alternatives if you make a decision fairly soon

The full timer is only an enquiry at this point, and could very easily decide not to choose you, so maybe go through the motions - visit, working out fees, deposits etc and see where that takes you - normally the signing contracts and taking a deposit stage is enough for 'serious' enquirers to back out
It could be that during the visit/s YOU decide you'd rather not take the full timer - don't click with the parents, get a bad feeling, whatever.

You could still have 2 more part timers on the mornings 8am - 12 or 12.30
I once had a mindee 6am - 12.30 that slotted in really well - apart from the early start

If you take funding, you could offer the mornings as a 3 hour session 9am - 12noon to two people that could potentially lead to more hours/future business

If the full timer left 6 months down the line, you'd loose a lot of income in one go. If a part timer leaves, I find it less stressful on the finances


Personally, I would stick with the part timer that has already signed, but that's more because I work on 'first come first served'

Good luck whichever way you decide x