Our futures daughter in law is planning a reception that is way to expensive how do we get her to tone it down

Are you paying for it? Then tell her what the budget is and kindly suggest areas that she should reconsider like no. of guests or the entrées. If she is paying then you really can't do that.

If you are contributing $$ you can set a limit on what you can give, but you can't tell her what to spend it on. A "gift" of money is still a gift, after all.

If you aren't contributing financially, there is nothing you can do. If it's their own possible debt that worries you, try speaking gently with your son.

Remember to tread lightly, this person is becoming family and you have a lifetime to spend with her.

I totally agree with the above posts... if you're not paying, then let her go, it is her wedding. If you are paying, just give her the money you would have spent on the smaller reception and have her chip in the rest.

I vote the same thing.

You paying - hand her a check for your budgeted reception amount and let her deal with it.
She's paying - butt out.