Feeding time for the old girl....

Minnie is our older dog, she is 15 now, and is at the stage where she is getting quite forgetful we think.
At night we feed her, then a while later in the evening she seems to forget that she has eaten and goes and sits by her bowl and cries and moans. So we feed her again, and so it goes on, until she wanders off to her bed and goes to sleep. It is not a hunger thing , as she sometimes only eats one or two biscuits.
Our other dog, who is alot younger is always on the watch for the left overs!