If it keeps going at the same rate:
The grandma will be a great grandmother at 45
A great great grandmother at 60
Great great great grandmother at 75
and so on....
Haven't you heard? Theres a "New Pit of Doom" Theres sea creatures, wolf spiders, and chainsaws, and giant paper shreders to further cut them bitches up. Thank You :) *eye twitch... Also spread this around so this New Pit of Doom can live on forever.
The grandma will be a great grandmother at 45
A great great grandmother at 60
Great great great grandmother at 75
and so on....