The child is expressing its sentiments in the song:

The child is pleading her mother to take a day off for me and be with me. 

You alone are my brother and sister also. 

Dad also goes to office and comes by 7.00 p.m.

I have nobody to play with. (No siblings) . Why do you want to go to office? 

You also leave me at the creche and go to the office. 

I'm left all alone. 

I don't want toys nor I want sweets. 

Still, If you leave me and go, I won't wave (say bye) at you from the window. 

I'm all alone.