Not very beautifull girl. what shud I do?

a girl loves me vry much...n i also love her and want to marry.evrything is fyn...she said to me that she loves me..n i said yes to her, but she is not vey beautifull and has not good face.all in my family are so beautifull...... sometimes I`m attracted to other girls.dnt knw why....but i love her so much...she is mine.....wht shud i do...?...shud i say to her you shud be more beuatifull...or wht plss help here......