Unregistered

I own a print of an oil painting that was given to me by my great grandmother and am unable to locate a signature on it. It's very dark consisting of mostly blue tones. It depicts a mother in common 18th century clothing and her three daughters. To the left there is an infant in a bassinet and two young girls with the mother, one of the girls is in a chair with a doll. The group is sitting next to a window with a white curtain. If anyone has any clue I'd love to know! Thanks