Switching from Enspire to Kirkland’s

Hey ladies. My daughter will be 9 months this week. She’s been on Enfamil Enspire since she was a newborn. We have recently decided to switch formulas because it’s hard to keep affording each week ($40 a week per can). We decided on Costco brand Kirkland’s formula after reading some pretty good reviews on it. My only issues with it is it doesn’t have some of the same ingredients found in Enspire that mimic close to breastmilk (yes, I’m aware nothing can really compare to breastmilk) and Kirkland’s doesn’t countain prebiotics and probiotics. How can I make up for this deficiency in those areas? She’s nearly 9 months, so she will be off Formula in 3 months, but I’m just concerned she’s not going to thrive development-wise like she was on Enspire. She’s way ahead milestones wise and I know I can’t credit formula for that, but a stupid part of me thinks it is and she’ll fall behind on another brand of formula lol.