This is the only time in 2020 that I've fed my boa to date. He ate 2 days ago. Your boa WILL NOT drop weight. You have a healthy snake and if you read through the COMPLETE and MORE COMPLETE BOA CONSTRICTOR books you'll likely see the "seasonal Changes" part.
My boa hasn't had a meal since October and that is completely normal. Holding some waste is also normal.
That boa looks great from what I see in the pictures.
I'd slowly space out the feedings she's old enough. She'll do great.