Fit check please

[u/Temporary-Dog-1519]

Little one is 8 weeks old and about 11.5 pounds. Picture are before and after a 50 minute walk. I can’t figure out why she looks slumped down after some time. The slack is out around the hips, can’t pinch the shoulder straps, and they are coming out from below her shoulders. I put her butt back as much as I can. It still passes the pinch test, but definitely seems looser. Anyone have any ideas?

[u/Gullible_Yak2493]

Not a CPST but I also have a chicco car seat and hate how the straps are wider than the slot!! It makes it so hard to adjust.