I think it would be lovely to have a gathering and gift giving to celebrate their certification, but would caution against doing a twist on a conventional shower.
Becoming a foster and/or kinship care provider is a very complex, long, often unstable process. It is important, valuable and rewarding, but we often don't see the results that hope for (ex. adoption, easy transition). While the children's parents may not take the initiative to enact the change they need to in order to regain custody, a person of kin may take the children. Children's grieving cycles are delayed, in comparison to adults, and often it takes a month before they begin grieving their transition/trauma. It is also the beginning of a long emotional and physical journey for your friends. As pointed out by Christine, the process that leads up to adoption can be very difficult and uncertain.
That you and your friends want to welcome these children into your community is *fantastic*. That warmth and love helps to stabilize children in transition/trauma. I encourage you all to finds ways of doing so that are real, but that doesn't presume their permanent placement with your friends.
I think it would be wonderful to help her set up her home and subsidize necessary supplies/clothes/toys. However, because it is likely that these children may not stay with her, decking out her home with individual gifts might not be helpful in the long run (emotionally or materially). I would also ask her what she needs and what is provided (or has the potential of being provided by the state) already.
Some gift ideas I suggest are:
-a few specific, special toys and clothes for her current foster children
-a feelings chart
-books for children that pertain to emotions/foster care: "Duck and Goose feelings", "A terrible thing happened", are a few of my favorites. Here is a link to more:
http://www.amazon.com/gp/search/ref=sr_nr_scat_4_ln?rh=n:...
-Books for children: You know, all your favorites!
-Toys: Mostly gender neutral and for a wide variety of younger ages
-Art Supplies
-Play house, play kitchen, Doll house (great for unintentional and unguided play therapy) - craigslist often has cheap, gently used versions
-Blocks and large leggos
-Gifts to pamper mom and dad. Bath salts, journal, coupon for a massage etc.
You sound like a fantastic friend!
Ephie (kinship care provider for my 3 y/o niece)
*this has been edited*