Can a woman develop normal lactation without having a baby?

Not normal. Can develop from overstimulation of the nipples, medication side effects that increase prolactin levels, or a pituitary adenoma.
YES. Of course. Get a hospital grade pump. Pump every 3-4 hours. Follow a program for induced lactation. Enjoy your Adult Lactation Relationship.
Yes. Adoptive moms have occasionally achieved this ability with the help of their OBGYN and lactation specialists. It involves stimulating your body with hormones and educating you in the process. If this is your goal it is possible with help.