When I was pregnant with Sophia, only 21 months after delivering Kathleen, I usually got two responses when people understood how close they were. Either they wondered/asked if Sophia was a surprise or told me how fast friends the girls would be.
Personally I hoped that the latter would come true and eagerly awaited the advent of
Kathleen's new best friend that wasn't me. When Sophia joined our family, Kathleen was mildly interested, but didn't see much appeal to her new sister. Sophia was entertaining sometimes, but nothing close to a playmate especially as I was much more interesting.
Once Kathleen learned to talk, I was vastly preferable as the answer to all of her questions and Sophia a mere annoyance. After we moved to Cairo and Sophia learned to walk, the two were twin satellites in my orbit. Upon our return following Edwin's birth, the relationship grew antipathetic and Kathleen started violently shoving Sophia upon little or no provocation.
Recently, with the consistent application of firm punishment to any physical violence, the girls have become friends. Kathleen is old enough to be quite imaginative and direct play, and Sophia is old enough to understand Kathleen's directions and be a willing participant in whatever scheme Kathleen has recently thought up.
One day, after finding some ribbons to act as a leash, Sophia became Bow-Wow (or Puppy Surprise) the puppy and Kathleen The Owner. Our prayers for several days included gratitude for The Owner's puppy and parents to teach The Owner how to take care of the puppy. Once during a prayer I mistakenly referred to Sophia by her given name, and she indignantly shouted me down mid-prayer "I'm not Sophia!! I'm Bow-Wow!!" I corrected myself and finished the prayer without profaning my petition with laughter.
When my Aunt Bonnie was recently in Cairo for a visit, Kathleen commandeered her into role-playing. We had watched Chitty-Chitty Bang Bang a few weeks before, and so that afternoon we were all characters from the movie. Sophia was Jemimah, Kathleen was The Father, I was Truly Scrumptious, Edwin was the Child Catcher and with nobody else left, Aunt Bonnie was Jeremy. She had a difficult time remembering to call her great-niece Kathleen father and was chastised repeatedly for the offenses.
When the girls hover about me like flies, I can use their newfound cooperative creativity to find some other amusement other than my company. Presently they are stinky bears who are valiantly trying to take baths to get the stink that just won't come off. Every time they ask me, I seem to still smell the stink and send them back for another round of bathing.
So all of you mothers of young children close together, take heart. One day your children will also become friends. And then you can have some sanity, if only in three-minute snatches while the bears are bathing.