Cot, playpen, car seat (8 month baby) (Berkhamsted HP4)

We are having a niece visit from overseas with her husband and their baby who will be 8 months old when they visit in May. We have retained some stair gates but realise we have nothing else useful for them - so any of these would be really helpful. I am happy to return them after the visit (ending early June) if that's preferred. Hoping someone can help! Thank you.