That's a pretty emotional first post.
The fact that an airframe is 19 years old does not mean that it is automatically ready for the scrap heap. There are many commercial aircraft older than this that are still in use and perfectly safe to fly. How old was Concorde when retired? How old are the NASA shuttles?
The keyword is 'maintenance'. Saudia is a half partner in Yemenia. Saudia's safety record is second to none and I would seriously doubt that they would put it on the line.
Xeque, Reuters reports that the plane was inspected in France in 2007, some faults were detected and since then it has not flown in France. So poor maintenance cannot be ruled out yet.
Here, a news channel (Globo) is reporting that there was some sort of passenger's organization that has been complaining about the lack of adequate maintenance by Yemenia, and had scheduled *before the crash* some sort of protest against the company in France.
Cannot confirm that from any other source yet.