urgent advice is required please!

by CIN
(Australia)

My 6 year old female Jack Russel is usually as a very active, happy and smart dog v. She is slightly overweight though, but has been for a few years now. I moved out of home 3 years ago, but I visit regularly.

A baby was born in the family nearly 3 years ago and since then all the attantion has shifted to the baby when she is around- most of the time.

Today she is very quiet, head down, eyes down. refusing to play or approach anyone, except me. However, her feeding and bowel habits are as per usual.

This is very much not like her. She is usually running around the house, playing fetch, jumping on everyone's laps, barking and is very playful.

What could it be?

Thank you