You can perhaps tell your parents after you announce it to them that hers are not that enthusiastic. They could help you.
Also how unenthusiastic are they? Like do you expect them to forbid her from seeing you if you tell them, or they'll just frown a little?
Also how unenthusiastic are they? Like do you expect them to forbid her from seeing you if you tell them, or they'll just frown a little?