Brian Rothhammer
AH fanatic
Cannot be a Mauser/Rigby, because of the forwards position of the bolt handle.
Also the position and style of the front sling swivel, mounted on the stock, is an indication.
I think, it is a Mannlicher-Schoenauer Model 1924 in 10,75x68,....
In 1930 the only M-S caliber legal in Kenya.......to take lion and elephant.
HWL
The sling swivel position, being apparently screwed into the bottom of the stock rather than a 'stirrup' coming down from the barrel attachment point, made me wonder for a bit if it's a takedown model. It looks like a single trigger but I can't make out a TD lever on the trigger guard at this resolution and a TD pin would seem likely to have caught some light as she moved the rifle about.