A riddle about two mathematicians

Two mathematicians meet. They’re old friends, so they get to talking about life.
 Before long, one asks the other:

• Q: What are all those presents for?
• A: Well, it’s my three children’s birthday today.
• Q: The first asks … How old are they?
• A: The second replies … The product of their ages is 36.
• Q: The first thinks for a moment and says … That isn’t enough.
• A: The second says … The sum of their ages is the same as the number of windows in this building.
• Q: The first thinks for a moment and says … That isn’t enough.
• A: The second says … The youngest is Evička.
• Q: The first thinks and says … Ah, so their ages are …