I don’t know what to do anymore

We got our dog about two and a half years ago and she’s mostly the biggest sweetheart. However, since our son arrived and we’re unable to give her the same level of attention she’s begun acting out. I wasn’t frustrated and I’ve tried to set aside time to show just her affection so she knows that’s she’s still loved. My husband and I work opposite each other and are only home together one, maybe two days a week together so sometimes it’s really hard getting her out enough since we live in apartment. I tried paying my sister to give her walks but my sister was frequently forgetting about her and I can not afford a regular dog walker. Lately she’s becoming more aggressive with my son, like trying to nip at his butt and such if he bumps into her (please note we do correct actions that aren’t nice or may be painful that my son may do to our dog). This past week she even managed to pull at just the right time and got out of my grip while I was taking her for a walk with my son. I then had to pick up my one year old and try and chase after her because she refused to come back to me and instead kept running to a family member’s house a couple blocks away. With scheduling issues we are unable to do doggy training but have been trying to work on things at home, but I can’t keep chasing after her and even two and a half years later she still is pulling really hard on her leash at times which will even knock me over. I’m beginning to be at my wits end. At this point I’m really thinking of rehoming her to a family with a yard who can be able to provide her with more one on one time because I really think she needs it based on her actions.