Is it V5 If so the parents will come on at times like if there Mateing I dont exactly know when they come on because they'v never come on mine either.
If its V3 up to V4.5 then when you get on to the next gen then go on Tamatown and typ in your log in code and click on the 2 little houses what say parents Grandparents then type in the code and visit them...
Hope I helped
TAMAWHO!!??