Hi Eric,
the little problem here now may be communication,
getting a PT job to work at night...
To avoid her or to bring back more money?
If the reason is to bring back more money,
then it's positive, you should discuss with her.
If to avoid her, it's not encourage.
She may be real bored at home,
facing the little one, can't go out.
Rem the time during courtship, she has all the freedom?
Your pretty girlfriend without flabby tummy?
Talk to her, get someone to help look after the little one,
bring her out, movie, dinner, shopping...
Last but not least, ASK HER WHAT SHE WANTS! What she want to do, work or be a stay-at-home-mum like now...
Pamper her once a while, you should get what you need.