4.2 NT

My sister just had her scan with an NT of 4.2. She had a miscarriage less than 6 months ago and is extremely stressed. Baby was moving around a lot so was difficult to do measurements. She’s currently awaiting for a call in regards to blood test. Just wondering if anyone had around the same NT and gone onto having a successful pregnancy with no issues that a higher NT may increase chances of. No family history of this either. She also has a 7 year old who’s perfectly healthy. She is 36 years old. I’m hoping because it’s not much higher perhaps measurements were wrong as baby was moving around a lot?