Vinegar is the best method of ridding mould as it kills the spores not just removes what you can see. (1 part vinegar to 1 part water or pure if the problem is really bad). If you have a really bad issue with mould (my house was filled with it and we could smell it but couldnt find it and have since had a daily battle with it) Clove oil is really good, but this CANT be used during pregnancy.
Heating is the only thing I have found that is stopping the mould, we have had a heat pump put in and if we run it everyday all day and night we have the mould at bay. It all depends on what the cause is of the mould (condensation build up/moisture).
Good luck and I hope the real estate fixes it for you. You need to remind them that mould is dangerous and can cause harm to your families health.