I had my kids at 49 and 51. Now they are tweens and parenting is harder than ever.

Courtesy of Tracey Kahn

• Tracey Kahn, a single mother by choice, gave birth at 49 and 51.
• The younger girl is a tween, and the older will turn 13 next spring.
• Kahn, 61, has found parenting more challenging as her daughters have grown older.

This as-told-to essay is based on a conversation with Tracey Kahn, 61, a publicist and the owner of a fine jewelry company in New York City. It has been edited for length and clarity.