Ahhh the sleepless baby days, I feel for you.
Exclusively breastfeeding both of my boys resulted in two very different sleeping patterns. Of course that is because it was not the nursing them that caused them to sleep the way they did. I caution you not to believe that bottle fed babies sleep better and to beware of the promises of cereal fixing it as well. My first son never slept well until after 2 years old and his removal of his adnoids and tonsils. My second son (also had his adnoids & tonsils removed around age 2) was a wonderful sleeper from about 3 weeks old on. Both were exclusively breastfed for over 4 months before introduction of baby cereal and breastfed in total for almost two years each. This did not seem to be an indicator for sleeping habits at all.
There are many ideas on getting them to sleep alone not all of which I feel are good for babies but you will have to decide what is best for you all. I do not personally recommend trying some of these until at least 6 months old. Here are some to consider:
* giving the baby something you have worn with your smell on it to lay on.
* letting the baby get almost to sleep while nursing by not allowing her to fall asleep at the breast (this does not work for everyone) and lying her down while awake. Gently rubbing her and rocking the bassinet while comforting her asleep. Picking up only to comfort and calm then return to the bassinet or crib and remaining close by. (This is NOT nor do I recommend the "cry it out" technique) Keep in mind that you will need to be able to follow through on this and if you are already sleep deprived you will likely need good moral support to pull this off. There is more to this but you get the idea.
* If falling asleep before fully finished nursing is an issue try techniques that keep the baby awake until nursing is complete. If the baby is full she may sleep better or longer although this is not usually the problem.
* look for signs of other issues:
-babies and small children should NEVER snore. If your baby or child is snoring you should demand to see an ENT to make sure there is nothing disturbing the airway and sleep patterns.
-look for signs of food allergies as what your eating might be causing her sleep issues (unlikely but worth exploring).
* keep track of how many hours in a 24 hour period the baby is sleeping. Keep a sleep journal (can be a scrap of paper if need be) and write down time feel asleep and time woke up over 24 hours. Look for patterns and make sure that the baby is sleeping enough hours a day to be well rested in total. Check with pediatrician if unsure.
God Bless,
R.
P.S. "Babywise" is a book that has been linked to failure to thrive in infants and has even been linked to infants deaths. From a medical standpoint alone It is not a book I would recommend to anyone ever!! Even if it is not directly the book or the authors fault in these cases, it seems to have contributed to it. The authors have no real authority or expertise and do not keep in mind that all babies are different. It is not just the forcing the baby to cry it out that is the problem with the book but the breast feeding schedule and forcing a baby to cry and suffer while hungry that was a major part of the problem.
Older babies (older than 6 months minimum) can in effect "cry it out" but it can have long lasting effects for certain children. SInce these babies are too young for you to know if they have any other issues to consider (ASD's or sensory problems to name a few) it is unwise to assume that this technique will not "hurt" them. In most cases they will be fine having learned that when they communicate the only way they can, with cries,that you will not always come. If you are okay with that message and feel they are old enough to "get it" than it is the right choice for you. I tried the cry it out with my oldest son and it lead to severe anxiety issues and more intense sleep issues. I have met a large number of mom's who had similar experiences and wish they had not tried it either. I just want everyone to be prepared for a possibly bad outcome. Dr's tell everyone to do this and they are not the one's who deal with the results, we are. It does work for some babies and some families will advocate it endlessly so it must work well for them. Follow your gut instinct on this!!