It’s the parenting guide for parents who thought they no longer needed one―for parents who worry as their 20-something kids struggle to grow up; who are saving for retirement but now have to reopen the bank of Mom and Dad; who look forward to downsizing but have a boomerang child living at home again.

And it’s the parenting guide that says it’s all going to be OK―just step back but stay connected, and don’t forget to take care of yourself. Kids may be taking longer to graduate from college, start a career, marry, have children, but it’s natural. Just as scientists a century ago discovered a new phase in life called adolescence, there’s now another developmental stage, emerging adulthood. According to Dr. Jeffrey Arnett, the world’s leading authority on emerging adults, and his coauthor, Elizabeth Fishel, author of Sisters and mother of two 20-something sons, the time spent in emerging adulthood actually helps kids become happier, healthier grown-ups.

When Will My Grown-Up Kid Grow Up? covers every aspect of life for an 18- to 29-year-old, from that first taste of independence at college to that time at the end of the 20s, when the majority of kids are settling down. It explains what grown children are going through―intense self-focus, instability, a feeling of being “in-between” mixed with a breathtaking sense of possibilities―and how parents should deal with these changes, from six ways to listen more than you talk, to money 101 (and why never to use money to control your child’s life), to troubleshooting their failure to launch, to, finally, the dos and don’ts of promoting a successful transition to adulthood.

Because yes, they really will grow up.