Automatically migrate to Family Sharing?

Before Family Sharing, my wife and I always used her iTunes account for all purchases, including iOS apps. Now that Family Sharing exists and also now that two-factor authentication makes it annoying to keep my iPhone authorized to her iTunes account, I'd like to find all the apps on my iPhone that were downloaded under her account, and re-download them under my account (by way of Family Sharing).

After upgrading to iOS 13, I keep getting prompted to sign into her account, presumably because some app on my phone was downloaded under her account, so it's only authorized to run if my phone is signed into her iTunes account.

Is there any easy or automatic way to find all the apps on my phone that are only authorized for her account, and delete and re-download them from my account so I don't have to stay signed into iTunes as her?

Unless I'm misreading your question, doing the following will make the process easier for you:

1. Launch the App Store app on your iPhone
2. Tap on your account at the top right corner
3. Tap on Purchased
4. Now you should see a listing for all accounts in your family group
5. Tap on your wife's listing
6. At the top, below your wife's name, you'll see two buttons All and Not on this iPhone
7. Make sure that the All button is selected
8. Now you'll see a listing of all apps^* ever purchased under her account
9. The ones that have the OPEN option at the right are the ones installed on your iPhone
10. Now make a list of the apps in question so you can delete them from your iPhone and install them under your account

^{* Accept for any apps she's actively hidden.}