It's about whether we can afford the loan + other costs that only arise with ownership.
That's fine. You earn well and also get through rough patches. However, I don't understand: if you earn €5000, have €2000 expenses, and then only want to count on €1200 repayment – what do you want to do with the rest? If you deduct €300-500 for additional costs, quite a lot remains. I would go at least to €1500 and change the repayment rate if the woman goes part-time. You are somehow securing yourselves threefold. Savings and inherited house should suffice alongside your own house. So just go full throttle with the installments.