ColorNote is an awesome, lightweight app that might work. (Android only) I prefer it to Google Keep and others - which are sometimes slower. It's also very, very easy to use.
https://www.colornote.com/
You could set that up on both phones, and set up the same sync email account for you both...so you can just sync each time you update and both of you will have the same info.
https://www.colornote.com/
You could set that up on both phones, and set up the same sync email account for you both...so you can just sync each time you update and both of you will have the same info.