We have a 2 year old female Miniature Schnauzer, Maggie, who has been house
trained since a pup.

There are 4 people in the house but I am the one who does most of the dog
walking etc.

Just recently, when I arrive home, Maggie has started to pee a little, I
presume in excitement.

Even if my wife knows I'm about to arrive and has her go out to pee first,
she still manages to do it.

Any suggestions on changing this behavior would be very much appreciated.

Thanks
Dan