However she is still in the process of getting the approval to move pet to Europe and the process takes almost two months 

The F visa is a Non Immigrant visa, and you have all the same possibilities for extensions as anyone else on a Non Immigrant entry (which means, very often, none). If aged over 50, you can possibly apply for a one-year extension based on retirement. If you have a Thai spouse or other close Thai family member, you can get a 60-day extension to visit them. An education extension might be possible, though difficult to arrange at short notice.

 

Depending on nationality and vaccination status, you could consider a "visa run" to a nearby country, returning to Thailand visa exempt. This can be organised quite quickly, the journey (including quarantine) taking about three days of your life. However, the costs in current circumstances are considerable.