Can this be done in Oregon?

[Tyler Cope]

So here's the situation, we have a family member that may be forced to sell her primary home. She is the sole owner of a SFR and owes around $150k on her mortgage. We're thinking of ways to keep her in the home for as long as possible and use equity in her home to help subsidize her living expenses.

Is there a way to add a second owner (joint tenancy) to the title and do a cash out refinance for between $200k - $250k with the new owner?  If possible, can the financing be done with only one of the current owners?  The home will easily appraise for $400k - $450k.  This means there is somewhere around $250k - $300k in equity.

Does adding a second owner (joint tenancy) generally trigger a tax reassessment?  

Can adding a second owner (joint tenancy) to title trigger a due on sale clause? 

Are there any tax implications in a situation like this? 

Looking forward to any responses from the creative minds out there!!