Your baby should begin sleeping through the night at about three months. But babies are learning and celebrating the time, and your baby could start with time that mother is not there to sleep period. It's called separation anxiety, and it is a normal part of development for most babies. However, it can be particularly trying for parents, as babies can be especially strong-willed, particularly about bedtime!
You could be introducing some baby foods at this time, and this might help your baby feel sleepy. Remember to present new patterns softly and slowly. If the baby is not going to sleep or keeps waking up and crying for you, then she needs to learn how to self-comfort, but not all at the same time. Ease her to the habit of sleeping alone.
Don't change your rituals. You are still able to begin with, a tub and feeding. Rocking and snuggling, singing, or reading – these are bonding times for mother and baby. If the baby doesn't fall asleep immediately, try placing her into her crib using the rocker or glider next to the crib, hearing or listening to her. You can stand at the crib and rub or pat on her back.
In a week or two, move a brief distance to the chair away in the crib, so the baby can see you. You can talk or read or sing. If she cries for over 10 or 15 minutes, then get up and comfort her, but put her back down into the crib, and go back to your seat.
Towards the doorway, move them farther away, in the following week or two. Even these modifications could be challenging for your baby, but be patient. This is a time when you are able to fold her laundry and put it away, talking to her, so she's aware of your existence, but your attention is not focused completely on her. This way, she can get accustomed to the idea of separation gently.
As seen on cerroreyesbadajoz.com, having a newborn is difficult for first-time parents, be patient and remember that the tiny person needs you.