Ultrasound pic

Hey guys my lil sis is 19 weeks pregnant and the doctors told her that they saw a white spot on the babies heart in the ultrasound pic and she's freaking out. Have any of you went through this or knows someone who did? We are very worried and she freaking out a little. She's only 20 and this is her first pregnancy any insight at all will help. I am also trying to conceive with my husband and it's been 4yrs. Its been a rough journey but God is in control. So keep us both in prayers.