Toddler sleep, waking in night

Hi, out daughter has always been a good sleeper however over the last few months has started waking regularly in the night. Last night she woke about 4 times and she opens her door and comes into our room and we have to walk her back into her room and get her back into bed and fall asleep. Sometimes we have to wait with her until she falls asleep otherwise she screams, she also sometimes does this when we put her down to bed. She is 2.5 years old and she has been doing this for like 2 months now, how can we get her back to going down to sleep first of all at her bedtime 7pm as she used to without us having to wait till she falls asleep plus the how do we get her to go back to sleep if she wakes I the night by herself and not coming into us as it's very tiring