Am I just being unreasonable for feeling this way

My sis in law went out with me & my hubby and said she wanted to bring my 14 month son back for sleepover at her grandma's hse. I felt offended that she didn't even ask for my permission beforehand. She only told us she wanna bring my son with her at the very last min while she was booking her taxi. My husband allowed her to bring but I didn't even had the chance to say yes or no. My husband didn't even ask me if I'm ok with it. Next day before she sends my son to my house, she went to shave my son's hair without informing me or my husband beforehand. I was really mad at her and she just smiled(as if it was nothing) and said that she wanted to surprise us with it. My hubby & I were actually planning to trim our son's hair in the next few days but my Sis-I-L just decided to shave all of my son's hair. She said that "Aiyo I pity my nephew. Better for him so he not stuffy with long hair". I felt like wow what a shitty reason. My husband was ok with it eventually. I feel so offended that my hubby n his sis don't even let me make decisions in things relating to my son.