My wife sold I-Bonds she jointly owned with her mother who died. where do I put the income and how do I figure the basis?

The bonds were purchased for $30,000 They were worth $41,904 when my mother-in-law died and they sold for 46,920 on 3/23/2017. The bank sent us a 1099 INT showing $16,920 for interest income.

How do I adjust this and where do I put it into Turbo Tax Premier?