No, I don't think so... I have read somewhere that toddlers can start having night terrors at about 2 - 2.5yrs old but I wouldn't think at 3.5 months old. Maybe she is waking because she suddenly has a pain. I found with my 3 month old that I would pick him up after waking screaming in what seemed to be terror and then out came a loud belch. Is it normally after you have just fed or is it well into the night?