Can she get pregnant if she has sex after 7 days since ovulation?

 
Seven days post ovulation is close to the outer limit of the fertile period. The problem here is how do you determine the day of ovulation? There is no reliable method to do so that you can practice at home. What if your ovulation was delayed by a few days in that cycle? This is the reason that the rhythm method is not a reliable method of contraception. It relies on estimating the date of ovulation. This estimate can go wrong. If you do not want to get pregnant, there are several inexpensive and highly efficient methods of contraception available. These have been discussed in earlier answers on this channel. Use of any of those methods along with the use of a condom will prevent both pregnancy as well as sexually transmitted infections.