Can a sole proprietorship business enterprise be a branch of a corporation?

My family runs a young corporation which is engaged in selling construction materials (my father and his siblings are the incorporators). My sister is in the process of putting up her own sole proprietorship business which would be engaged in the same, i.e., selling construction materials. The plan so far is that when the sole prop business starts operation, it shall share an office and a warehouse with our father's corp.

Now our concern is whether or not it is possible for a sole prop business to be a sub-branch of a corp? Or are these two enterprises entirely separate and different from each other?

DEFINITELY HINDI PUWEDE ANG SOLE PROPRIETOR MAGING BRANCH NG CORP. KAHIT S BIR AT LGU, DI PUWEDE IYAN

pero if you are talking about sharing the same office space ng sole proprietor at isang corporation, that can definitely be done pero at least me spacial physical division.

punta ka s city hall (business bureau) at ask this same question.