She is still very young and you don't have to wean if you aren't ready to. Don't let anyone tell you that you need to wean her cold turkey and then she'll eat. Probably won't happen. You'll be miserable, she'll be miserable and no one will be eating or sleeping.
But I would begin to establish good meal time routines. Remember that she is only 14 months old and it doesn't sound like she has a positive routine at this point so it will take some time.
Every meal and snack she goes to the high chair.
Make it a positive. Say and do the same things she quickly learns what to expect and what is expected of her. Tell her "Yeah! It's time for breakfast! Let's see what yummy breakfast mommy made just for you!" Something fun like that.
No tv, dvd, etc while she is trying to learn good table habits.
Continue to offer her a variety of healthy options. Some kids, especially very young like her, aren't very interested in solids.
I would also encourage you to learn as much as you can about infant/toddler sleep to help encourage good sleep habits. She needs to know how to sleep so that once you do wean (or even before) she is sleeping better. Check out Dr. Sears Baby Sleep Book (he also has one for toddlers) and The Baby Whisperer. I think she also has one for toddlers. Also, the No-Cry Sleep Solution had some very valuable info for nursing moms and helping baby sleep better.