right
I was thinking the same
her goal is revenge~
She's trying to make a fortune so she can start a business so she can have her own status, I think it's necessary in this case
Its not really years but yes its taking her life in exchange.. and its also very taxing for her body.. there's really an explanation why.. but i would reveal a huge spoiler so i wont tell.. instead i would say that her using the hour glass save her a lot of times in the future.. although there are times that you'll find her very irritating for depending on the hour glass..
Didn't she say she'd use the hourglass with care since it is literally taking years off her? :x