Come to think of it, there are. They're on page 98 (aka the part of the rulebook most Seneschals just end up ad-hocing, except for falling damage, since people usually only get into RoS for the combat). I will reproduce them here.
| Age | Age Category | Aging Target Number |
|---|
| 40-44 | Mature | 7 |
| 45-49 | Early Middle Years | 8 |
| 50-54 | Late Middle Years | 9 |
| 60+ | Old-Timer | 12 |
As to losing attribute points...
| Number of Successes | Attribute Points Lost |
|---|
| Fumble | 10 |
| Fail | 5 |
| 1 | 4 |
| 2 | 3 |
| 3 | 2 |
| 4 | 1 |
| 5+ | 0 |
So once you reach 40, every year you roll HT against the TN for your age category. If you're particularly unlucky, a fumble could mean that the moment you hit the age of forty you suffer from a critical case of old age and lose 10 points worth of attributes.
For a sorcerer, I would also have them make that roll every time they age after casting a spell once they're past 40 (although any attributes lost due to unnatural aging would be temporary, attribute points recovering at a rate of 1 point a week, as opposed to the permanent loss from one of the once-a-year aging checks. But that's just me).