She’s 79...I’m sure there were older speaker than that, but obviously her successor doesn’t have to adhere to any term limits deal.
The speaker is whoever can get a majority of the House to vote for him or her.
Any statute placing term limits would be overriden by another statute electing so-and-so to Speaker.
Yes, I know an election for Speaker isn’t really a statute. The President doesn’t have an opportunity to veto.