Husband gave 3 month old cereal in bottle!

Alright so I work nights so my husband is with the baby and he just texted me that she loved rice cereal but she is only 3 months!! I told him to wait until she's 4 months but he said she will be fine. He's had 4 kids before me and he said they were fine. is this true?? will she be okay?? I'm worried out of my mind right now!!