Article continues below advertisementRumer Willis opened up about the challenges of being a solo mom while keeping a smile on her face. "Just had a good cry in the woods ... some days being a single mom is hard," Willis, 37, captioned a tear-filled video posted to her Instagram Stories. "She is not hard (ever) but some days doing everything alone can be."Article continues below advertisementRumer Willis Shared Tearful VideoSource: @rumerwillis/InstagramRumer Willis shared a tearful video while enjoying an outdoor walk.