Tax Redemption Purchase

I will try to make this short and concise…
I own two duplexes. the mother of one of my tenants has lost her home (in Indiana) ina tax sale. She has until Septmber to redeem the property (about $5000). She has offered me the property if I give her $10000 and pay her lien (she would then move in with my tenant)
A tenant in the other duplex is looking to move out into a home, and in a previous conversation I said if I helped her find a home, I would facilitate her moving.
I gave her the address of the tax sale property and she would like to purchase.
Assuming I sell the house to her for $45000, and pocket the difference ($30K) is this considered an illegal flip? As I have not done anything this remotely involved before, would I need to do a double closing? And for the Indiana members, if all above board, is there a reputable title company that would do the closing?