Red Dead Redemption 2 features a Stranger Encounter called Fundraiser in Saint Denis. See the location and options below.
Quest Giver: Unknown Woman
Region: North-West part of Saint Denis
Requirements: Being in Chapters 2-6 (not available in Epilogue)
This unnamed Woman is sitting on a corner in north-western Saint Denis and wants to collect donations for an expansion of the Quincy Harris Memorial Hall and will talk to you for a few seconds about it.
The donation costs only $ 20 and will give you a small positive Honor boost.
You can, however, also loot her donation box, gaining a bit of money, but at the cost of negative Honor and the Law on your back. You should avoid that.
This concludes the Donation Stranger Encounter in Red Dead Redemption 2 (RDR2). For all other Stranger Missions check out the full Red Dead Redemption 2 Stranger Missions Walkthrough.