Do I still need to guide my daughters in their homeworks or should I let them do it by themselves? My eldest is in grade 6 and my youngest is in grade 4.

Same here. I was raised by my mom in a way that she lets me do what I need to without her help or supervision. Nonetheless, she will check my homeworks when I am done doing all. And when she checks, she does it with quality. And I meant not just making sure I get the answers right but also checking how I arrive with my answers (even checking if my penmanship is good).