hi Sabah:
How old is your kids? I also have the same problem but if he/she is below 9 months and can not sit without help, I found it is diffcult to find a shop for baby hair cut. I used to do it by myself. But if he/she is able to sit independently, I tried one shop in Tseng-Yi MTR Station once, it is called " Oasis". They have a section only for kids with kids TV program and cute hair cut chair for kids. They charged HKD 100 for baby hair cut.