Looking on the internet deeply has found these results:

be a big help to is the most popular phrase on the web.

be a big help in 1345,000 results on the web	be a big help to 1354,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
I think she could be a big help. Because I think I could be a big help. It would be a big help for us. Respecting such identities when electing their representatives in the European Parliament will certainly be a big help in improving the degree of representation and the relationship between the people and their Parliamentary representatives. I'm sure they'll be a big help. That would be a big help. My father can be a big help in getting cuts. If you could find one, it'd be a big help right about now.	That would be a big help. If you don't mind me saying so, I think I could be a big help to you. Because I think I could be a big help. My father can be a big help in getting cuts. It would be a big help for us. I think she could be a big help. That would be a big help to me, Misty. If you could find one, it'd be a big help right about now.

be a big help in

1345,000 results on the web

be a big help to

1354,000 results on the web

More popular!

I think she could be a big help.
Because I think I could be a big help.
It would be a big help for us.
Respecting such identities when electing their representatives in the European Parliament will certainly be a big help in improving the degree of representation and the relationship between the people and their Parliamentary representatives.
I'm sure they'll be a big help.
That would be a big help.
My father can be a big help in getting cuts.
If you could find one, it'd be a big help right about now.