Matthew49

As long as she
1) Doesn't enter the US (even to change planes) until she wants to stay AND
2) Does enter the US to stay before her K-1 expires (the expiration date will be printed on her visa; don't cut this too close, as flights can be delayed or canceled)
then you're fine.

without starting anew with the IR-1/CR-1.

No.
She cannot travel until she applies and receives either Advance Parole or Green Card. 
Means at least 4 to 6 months being stuck in the US. 
 
I mean she can leave but she cannot return to the US then. 

She can travel before or after the Visa is issued.   Enter the USA before the Visa expires.  Travel after entry is restricted for a period of time 

Thanks everyone!!!! God bless and Merry Christmas!🎄 

I agree.  I have seen many posts focused on the boarding pass and I think there might be too much emphasis on that sometimes.  I was speaking more broadly so people wouldn’t think they were sunk if they didn’t have them.

I won't speak to what IOs believe or not, but the point is they require documentation of meeting in person within 2 years prior to filing the petition.
 
That's not contrary to what you stated...I'm just reiterating this key point.

You can always bring the pictures to the interview.
 
 I don’t think they doubt that a trip was taken unless the case looks shaky.  I submitted passport stamps but otherwise sent just the travel documents (no boarding pass).  We did have pictures and passport stamps to match, so a boarding pass would be overkill.  
 
In the couple of years that I have read VJ, I have never seen a person say their visa was held up because USCIS didn’t believe that they actually travelled.  But again passport stamps don’t lie.