U probably need to get her more involved and talk to her more. She might be shy and don't dare to speak up. If u dont interact, she won't know ur needs, therefore always stay in the room and wait for ur cue. Set ur expectation and lay it out with her so she will know what she needs to do. U need to make her feel comfortable since she is staying with u. Once she feels part of your family, i believe she will start to open up and take initiatives. If she is taking care of bb as priority, all the more she should be more involved to know ur expectations n how to take care accordingly. It is very important to have 2-way communications and interaction to constantly know how she's coping and if she's settling well in ur house. She may watch tv with u if u allow her to and provided she finish her work for a start. Set a work schedule if she is also new else u may just tell her what she needs to do. Just like us, we need time to warm up and be comfortable among strangers, so don't worry.
Set a time frame for your helper. For example, if her working hours (by this I mean when most of her usual chores are done) is till 8pm, request for her to be within the vicinity during that time frame so that you can call upon her for help if needed. She's probably shy and still trying to get a sense of your family dynamics. You can invite her to watch TV with the family or hang out with the kids while everyone is out in the living room. But if she doesn't want to, it's okay and respect her decision. She could be tired and just want some alone time to herself.
Give her a timetable of everyday chores! I dont usually let her hide in the room before bedtime. I will normally get her to look after/ play with the kids when she's free; get her involved. Perhaps you wana talk to her, let her know your expectation.