Please help me... My MIL has a cocker spaniel he is just over a year.

I have three boys 5 and 7. The dog is lovely but the following is happening and it's worrying me.

She stops playing with the kids if the dog starts barking as it's jealous and she starts to stroke dog.
The dog is jumping all. Over the kids even if they are on chairs, or jumping up at them.. Nothing is said and the dog is scratching the boy's... Only to be told he
Its trying to take food off them at any chance.
They are not allowed to play with toys on the floor as the dog tries to eat the toys.

When they eat its under the table

If the kids are playing with him, then she is forever telling them ooo be careful.

I don't know what to do but I can see this going horribly wrong.