Hi...congrats to your DD and her DF!!
The first thing I would suggest is to take a look at the
Disney Wedding Website That will give you some ideas on what is available and the costs.
The first thing to decide, really, is whether she wants to do a custom wedding or an intimate.
She would most likely choose a custom wedding if she is having more than 18 guests (20 including the bride and groom). This option allows the most customization, but also has specific minimums to meet (usually $10k is the absolute minimum, but that could change in the next year or so).
An intimate wedding is more "economical" but it offers a bit less customization (although there are still options to make it more personal). The key here is that there is an absolute maximum number of guests (no more than 18 guests, 20 including the bride and groom).
You can call Disney and ask for more information, but they told me that the info on the website is pretty much it. Asking questions here is usually a bit easier (and faster

).
If your DD is planning something more than one year away, she can't really book anything with Disney, some locations (for ceremony and/or reception, if included) you can only book 8 months out.
Hope that helps...and keep checking back for other info, or to ask more questions!!