Okay guys I need to vent, and I need someone to tell me if I'm in the wrong or not. SORRY FOR THE LONG POST

Okay so my husband is a Christmas baby, his birthday falls today, the 25th. This year I wanted to do something different for him since we never really do anything for his birthday since it falls on Christmas Day and everything is pretty much closed. We are Hispanic so we celebrate Christmas with his side of the family on the 24th. We spent all day with his side of the family yesterday, we even opened some presents over there. My side of the family celebrates Christmas on the morning of the 25th so we spent all morning with them today, as we usually do. Well anyways, my mom surprised my husband with his favorite food and a birthday cake. After everything was over I decided to go over to my mother in laws house to take her some cake and some food that my mom made, when she seen the cake she nearly busted out crying! Her smile turned upside down and she literally almost started yelling at me! She told me that why didn't I tell her we were celebrating my husbands birthday at my moms house and that she wanted to spend time with him as well (which we weren't there for that, my mom literally surprised him with the cake, we had no idea she was going to do that) that why didn't we tell her we were there so she could've gone over and that she had been trying to go over to our house all morning to go see my husband (which would've been completely fine with me, but she never even called to ask if we were home or not) and theeen she gives me the nasties stare and she starts cryinnnng! I didn't know what to do! My relationship with her is so weird. We don't really talk, it's just little cordial small talk with each other and we leave it at that. But sometimes she does say little remarks like "how I took her son away from her too soon." He is 24 by the way. So for her to do that was SO SHOCKING to me. We spend my husbands birthday with his family every single year since we have been together (6 years) and we basically just eat and stay home when we do. All year he has been telling me that he wants to do something different this year, that he wants to go out and have fun. I was going to take him out for dinner and then to see what fun stuff we could do after but after all that our day got ruined and we didn't end up doing anything. I don't know if she feels this way because it's the first time she's away from him for his birthday (we moved out earlier this year) or do you think I was in the wrong somehow for not spending the day at his moms? I really don't know what to do I hate that she's upset at me.