Dear Abby: My younger sister, “Fern,” gave birth to a son three months ago. Since she returned to work, it seems like all she does is dump her baby, “Ricky,” on others so she can sleep with her special someone. I watched Ricky a couple of times while they ran errands, even though they have someone living with them to keep an eye on the baby. Fern works nights and her S.O. works days, but all I hear is that Ricky is getting watched by someone else. She’s always in the parking lot at work 30 minutes before we open although she lives nearby. She also volunteers for extra work as often as she can. She has struggled with mental health and alcohol abuse, so I’m worried she may have postpartum depression.