Wife and mother-in-law dilemma

Throwaway account -I live with my wife and mother & father in law. My wife has a 3yo daughter and I'm looking for some advice or to help find some understanding.The 3yo frequently wakes up in the early hours of the night and cries for attention, my wife usually responds by going in her room and calming her down, but sometimes the mother in-law responds first. I'm generally unwelcome in the room with her as she really just wants her mom or grandma.Recently there was a rough night where the 3yo woke up for the 3rd or 4th time that night and the situation escalated to all three of them (wife, mother in-law and 3yo) in the same room with yelling and crying, 3yo is awake and crying about something they believe is trivial and both of the adults have their way of dealing with this, but the mother in-law always wins out. The solution she had come to was to pull the 3yo out of bed, throw her pillow and blanket on the floor, put the 3yo on the ground and spank her as punishment, telling her that she no-longer gets a bed. This has been the 'solution' a number of times and typically ends with tears and putting the 3yo back in bed after a moment, I guess just to scare her into settling down?I'll be brutally honest here and declare that at no point do I ever believe it reasonable or necessary to cause physical harm to a child. Call it smacking, spanking, paddling, beating, whatever you like, my take on the matter is that an adult has decided that no amount of reasoning, talking, distraction, coercing, ignoring, soothing or yelling will work any more and that the only recourse is to cause that child physical pain. The adult made this decision and the child is defenseless. I'd hate to imagine someone twice my height and with far more strength than I have throwing me on the floor, pinning me down, and smacking me when I was upset.All that being said, this was the course of action that was chosen and at that late hour I couldn't lay there and do nothing, genuinely I'm concerned for the 3yo as the adults involved have terrible tempers and I knew a spanking was on it's way. Usually I don't step in but my concern for the young girl made me feel terrible, so I went to the room to try and calm things down. This was obviously a bad idea. My wife wanted me to leave, the mother in-law was still yelling at the child and eventually stormed out, cussing me out as she left because it's not my place to be there. I tried to stay and soothe the girl but as usual she really isn't responsive to me being around in the night. There was an argument following where I did my best to explain that I was concerned and wanted to try and help, probably foolishly, but they both let me know I'm unwelcome in these instances and shouldn't get in their way.Outside these night time events our relationship is good, it's challenging to be the parent for a child who biologically isn't yours but I don't find being with her difficult, I'm more concerned that I'm doing what's right in the eyes of her mother and grandma. Me and the 3yo play, talk, learn together, go places together, I bathe her and she calls me dad and things feel right. I even put her to bed some nights and read stories etc.My dilemma is that I won't let myself sit idly by while she suffers, even if she is being a handful sometimes, but there's also nothing I can do right in these instances. I can't lie there and listen to her sobbing and crying, hearing the adults stamping their way down the halls to come and drag her out of bed and spank her to get her to shut up.Given that my wife lets her mother handle these things as she likes, and neither of them want me to do anything about it, there aren't any other people I can talk to about this for advice, even if that advice is to just shut up and deal with it, I feel like their view on things is very one sided so discussing it is always a bad idea.I've been blunt in recounting this, for obvious reasons, and it makes me sound distant from them all, especially the 3yo, but that's not the case. Everyone knows and treats me as her dad (except the mother in-law) and we just want to be our own family with plans for me to legally become the father in the future. We're getting our own place soon but the issues I'm facing now are a concern for me in the future regardless.Any thoughts are welcome, it just feels useful to put this out there. via /r/Parenting http://ift.tt/2kveiLW