the loan itself is not a gift since it will be repaid. however, under various sections of IRC 7872 if the loan is for more than $10,000 and interest at least equal to the Applicable Federal Rate (AFR) is not charged then the lender (you and your spouse) have additional interest income equal to the difference between the interest computed using the proper AFR and the interest actually received. Your daughter is treated as making a gift to you for this amount.
There are three AFR tiers based on the repayment term of a family loan:
(1) Short-term rates, for loans with a repayment term up to three years.
(2) Mid-term rates, for loans with a repayment term between three and nine years.
(3) Long-term rates, for loans with a repayment term greater than nine years.
The AFR rate can be found.
In the case of any term loan, the applicable Federal rate shall be the applicable Federal rate in effect under section 1274(d) (as of the day on which the loan was made), compounded semiannually. (table 1)
https://www.irs.gov/applicable-federal-rates
