The wonderful Wendy Clarke (who only lives down the road from us) has created a fabulous tool: character timeline spreadsheet. Well, her hubby has set it up, but go check it out here where Wendy is generously sharing the tool. You can download the spreadsheet and start using it yourself.
The Indoor Writer is always get characters ages wrong and timelines out by several years and her trusty proofreader (Handsome Hubby) doesn't alway catch the howlers. So now she has no excuse.
Thank you Wendy!