Is this landlord a good one?

First week, I've noticed that the windows were dripping with water from the inside and didn't think much of it.
Third week, I've noticed it hadn't stopped came to the conclusion that it's cold outside and a bit warm in here, so of course that can happen.
The fifth week in, I've noticed dark "spots" all on the windowsill and around it.
The sixth week, the landlord told us that if we see any water on the floor, make sure to clean it up so it won't create mold.
The fourth week, there was a small puddle on the floor of me and sister's room.
Going back to the sixth week, I've now noticed that those weren't black spots on the windowsills, that was mold.
They're still there.
My little sister has mold in her room, on her walls. It's not that bad, but it's there. Both the pollen and the mold are affecting her eczema. She even has a big bump under her chin that she tried to pop.
In my little brother's room, he has mold on his walls.
What are so similiar about these, is that their beds were on the walls, where the mold is.
For some reason... there's no mold in my room, besides the windowsill (I hadn't checked the windowsill).
I am not going to jinx myself by being all so happy about there being no mold in my room.
Maybe there's no mold in my room because I always keep the fan on in my room and it's always somewhat a bit cold in here.

Don't you think that the landlord should have told us beforehand about the mold?