Also I would want to have a discussion on how they will ensure they are ‘ready to move on’
Are they planning to buy, rent?
What do they need to do to achieve that?
Fwiw, I don’t agree about the ‘charge them full price so they don’t feel comfortable at home’.
For one, there are some downsides to be living with your parent(s) and it’s not easy to adjust to ‘being back home’ for them either. I doubt many people will be happy to stay there for ever, esp with partner and child. Unless they are been babied and have everything brought to them on a golden plate iyswim (by that I mean everything done for them, most stuff bought for them etc…)
And then, if they are living in their own paying normal market prices, they will be able to get benefits they won’t get by staying at the OP’s. You dint want to make their life so hard by being at home that they can’t save for a deposit (house OR rental) etc…. Because then they won’t be able to leave anyway.
Id agree that you might want to put time limits though.
Something like let’s do that for 6months and review if it’s actually an acceptable compromise for everyone/YOU. And then another 6 months but no automatic ‘you can stay here for ever and ever’
As said before, I’m not worried that they will never move out. I’m more thinking that your situation might change and you need to be able to tell them to move out for own sake Wo you feeling guilty about it, feeling you can’t etc….