Hello,
Come to find out neither my nor my wife has the master password anymore to her vault. She does have access with her PIN on the mobile app. However, is there any way to either reset her master password, or exfiltrate her passwords from the app?
If she can access the vault via the mobile app using a PIN, do that and immediately export it (Settings, Vault, Export) in encrypted .JSON format. Then send that to your cloud storage (ideally also encrypted) so you have a backup stored externally to the phone.
Start there.
@vontastrophe Welcome to the forum!
Unfortunately, there is no way to reset the master password (unless you and your wife are both members of a Bitwarden Enterprise Plan, and you are the admin of that plan). Exporting the vault data usually requires knowing the master password, although it may be possible to circumvent this requirement in the browser extension and web vault.
No — @vontastrophe, you shouldn’t export the encrypted .json format, because you cannot import such a file into a new Bitwarden account (and your wife may have to set up a new account). Regardless, she won’t be able to export from the mobile app without knowing her master password.
If all else fails, manually open each vault item (starting with the most important) and copy the information.
The first thing to do is to check all available devices (computers, tablets, etc.) where your wife might have previously logged in to Bitwarden on a browser extension. However, it is essential that you first disconnect the device from the internet (e.g., unplugging any Ethernet cables and disabling WiFi) before opening any browsers to check for this. If you find any browser extension where your wife’s account is still logged in but locked (i.e., the prompt will say “Verify Identity”, and the button will be labeled Unlock), then see if you can unlock the vault using a PIN or biometrics. If so, please keep the device disconnected from the internet while awaiting further instructions.
Your second option for attempting to recover the vault data is to try is the “Login with Device” feature. This may be possible if she had ever previously logged in to Bitwarden using the web vault or a browser extension on any device (and if browser cookies have not been cleared since she last logged in). To pursue this option, first reconnect the device to the internet (if disconnected). Then, on her mobile app, she should go to 
Settings and enable Approve login requests (in the Account security section). Next, start the log in process on the previously used browser extension or browser (web vault) by entering her email address and clicking Continue. On the password entry page, instead of entering a password, click Log in with device. If the browser or browser extension is recognized (i.e., if the cookies have not been cleared since your wife last logged in there), then she should see a prompt on her Bitwarden mobile app, asking her to approve the login.
Let me know if any of the above worked — i.e., if she was able to unlock or log in to the web vault or a browser extension in this way. If so, I can provide some instructions for how to attempt an exfiltration of the vault data.
@grb of course, you are correct. I forgot that without the master password one cannot restore from an encrypted backup.
@vontastrophe sorry if I added confusion. As soon as I saw that you are able to access the vault on the phone via PIN I wanted to get something to you quickly as a start.
