ask him is who? i have no one....
you mean, she wouldn't like the ring you choose?
for a general guideline, you can choose a simple white gold one
with a diamond on it. This one is one piece suits all.
It doesn't matter how many carats the diamond is, what matters is
your sincerity and your love.
All in all, give her time to consider, respect her decision and
hear what she has to say. Sometimes a lady takes a longer time to
say YES but it doesn't mean that she doesn't love you.