How can I balance breastfeeding on demand and weaning my infant off of breast milk?

Don't be in a hurry! The simplest, most natural way to wean is when your child initiates the process, usually around when solids are started. But if you're ready and they're not, try slowly tapering the number of nursing sessions every two or three days by replacing a nursing session with an alternative meal from a bottle/sippy cup/other foods (if ready). With luck, she'll be too busy with new experiences to notice!