For those with babies home on oxygen…

Hi! I have twin girls that are 3 months, 6 weeks adjusted. They did 15 days NICU time and my one girl needed CPAP right after birth for about 8 hours and then being put on a nasal cannula, and my other girl ended up needing oxygen by day 6 due to sats dropping while feeding. They were sent home while still on oxygen (.12 liters and .03 liters) and we were to work with their pediatrician on weaning them off. He doesn’t know much of anything, pretty much just asks how they’re doing and if I want to take them off- sooo I don’t really know what I’m doing or what I need to look for other than high sats 24/7. How did you know your baby was ready to come off of oxygen? What “room air” tests have you done? Did you work with a respiratory therapist or pulmonologist? Please let me know! I don’t want them to be on it longer than necessary but I don’t want to do any damage😢