Is it ok to only use the stroller and not the car seat for walking , for a 4 months old

up to you. I preferred the car seat inside the stroller just because I felt he was more secure in there but it's up to you mama

I agree with above, as long as her head control is good, she's strapped in well, she's leaned back enough and is not flopping around she should be safe 😊 If I remember right we started ditching the car seat in the stroller when Melody was 5 to 6 months old

as long as there secured in i used her baby blankets to help suport