Here's a resource from SANDS that may help:
http://www.sands.org.au/Assets/Files...20and%20Family[1].pdf

Acknowledging their child and saying his/her name is very important. Maybe a card to say how sorry you are and that you're thinking of her and her partner. Christmas this year (and every year) will be hell, so any support will help.

Also understand that she may not be able to be around pregnant women or babies. Don't take it personally. It's just part of the grief.