As your baby gets bigger and more talented every day, it’s important to remember that every baby develops at her own pace. It’s completely normal for a baby to develop more quickly than the average in some areas, and to take a little longer in others. your baby is only human, after all - she can only learn so many things at a time. If she decides to take some time to really get serious about her fine motor skills, it only makes sense that she might lag for a little while on her language skills. Once she has mastered the skills she has decided she needs to master, she will have plenty of time to catch up in other areas. And as will be the case for the next several years, the more interaction with her you have, and the more you let her play, the quicker she will learn.
It’s no good for either you or your baby for you to be stressed about the speed of her development, but that doesn’t mean you can’t help her out a little. Making sure your baby gets plenty of well-supervised tummy time will help to make sure her trunk gains plenty of strength and control that she will need for a whole range of different types of motion, like raising her head, neck, shoulders, and, eventually, sitting up entirely. Free-play time where your baby isn’t strapped into any kind of seat or device gives your baby the chance to stretch and build out all those brand new muscles, too, and to explore all of her admittedly pretty limited options for moving around.
You can encourage other areas of her development a little more actively than just by keeping an eye on her while she rolls around on the floor. Her vision is still developing, and while she can see a lot more colors than she could when she was born, she probably still has a preference for high contrasts between colors. This means cloth books or board books in black and white, or with dramatically contrasting colors, could be a big hit right now, as well as good stimulation for her developing vision.
This point, coming up on the 6-week mark, could be around the time when your baby starts to develop a bit more of a regular sleep schedule. This doesn’t mean it’ll be the sleep schedule you were hoping for, but at least it might be a little bit easier to plan around.