“roommate” help

My husband and I are split on the topic (depending on the day) and really are just curious what others think.

Background:

My older sister split with her SO last May. He left her in financial ruins so we graciously took her in while she gets back on her feet. I was 6 months pregnant. LO is now almost 7 months. She’s a dental assistant and works 4 days per week, longer hours. We have no expectations she help out during that time. She’s off Fridays and is typically home weekends as well and stays up all hours of the night. We go to bed at 9pm every damn day because we’re freaking exhausted lol. She shares our upstairs. LO is in far bedroom, she’s in the middle and she’s also taken over my husbands “man loft”. She pays no rent, we do all the cooking, and she rarely helps clean, though she’s responsible for her upstairs area. We get $100/month from her to help with groceries; we buy any take out we all enjoy. She does watch our LO on Fridays when my parents aren’t able to, maybe once a month.

The poll is for this...

On the nights she’s doesn’t work and is here and we’ve been up and down several times with a fussy teething babe and she’s sitting there watching tv listening to her cry, would you think she should step in and help to give is a break or not?