Thanks all the same.

Please I am looking for an en-suite room in a shared flat around Woking Surrey, UK. Kindly let me know of any opening. Thank you

It is easier to judge others so badly when we are not involved.
Going by her name, she likely comes from a culture where the man foots a greater part of the bill for the wedding.
She is concerned with contributing 80% of the bill, we don't know how much this amounts to and so should not
accuse her of wanting a fairy tale wedding.
More so, for such concerns to come up, she may have some information about the guy as regards finances that we don't have.
If the actual tone of 'shebi you have money' is true, I don't think that should be the right way to go about it.
She said the rent was due in September anyway, was there any concrete plan on ground for a new place or was he just relying on her money.

@OP, you know more than we do about the man you intend to marry and what you guys share; do not base your decisions on the opinion of others.
Personally, I see no wrong in making some contributions.