Bedtime wetting / pull-ups

We started potty training just before her 2nd birthday. It took her an entire year to have few accidents throughout the day. She wore pull-ups to bed and 75% of the time she woke up with them dry. We encouraged getting out of bed and going, got excited when it was dry in the AM and even rewarded. She hasn’t wore a pull-up for her 1-2 hour long nap in many months and hasn’t had any accidents. But now, the last 2-3 months she’s been peeing her pull-ups again at night. We had a baby 3 months ago. Do you think the baby is why she is peeing them again? She always asks for chocolate milk and I tell her when her pull-up isn’t wet in the morning she can have some. Hasn’t worked.. I’m not really worried about it as she is only 3.5 but I know she is capable of getting out of bed to go as she did it before!! Her drinking also hasn’t increased any. & we’ve cut back on her bedtime milk from a full cup to maybe 1//4-1/2 cup..