Anyone can share how do working mummies cope with 4 years old to study at home?

Honestly it really depends on what your schedule looks like and how your child responds to structured time versus free play. My girl was the same age when I started trying to do some simple worksheets with her after work, and I found that a short 15 to 20 minute session after dinner worked better than trying to do a long stretch. Some mums I know prefer to use the weekend mornings when everyone is more relaxed and not rushing. The key is to keep it consistent but not too rigid, because at 4 years old the attention span is still quite short lah, so small and frequent beats long and stressful any day.