Ok I found the info on myfico report. Here it is:
Your oldest account was opened
12 Years, 4 Months agoFICO High Achievers [?] opened their oldest account 19 years ago, on average.
Average age of your accounts
7 yearsMost FICO High Achievers [?] have an average age of accounts between 6 and 12 years.
If my mother is able to add me as an AU how old does her cc need to be? If the account have had any lasts in the past or reached the credit limit, should I reconsider or.......try to use another card (my mother has approx 6 cc). How clean does the cc report need to be?