Your poor friend :( Where are you based? New babies with colic are utter, utter hell. I know, I have the battle scars to prove it! White noise, swaddling and slings are all good.
Your friend really needs to speak honestly to her HV or GP about her circs and how she is feeling so that she can get some extra support. I have accessed extra support myself (my HV only stopped coming to my house when my son was 6 months!). if you can point your friend to MN that's another great source of support.
Re the feeding and support, get her out to a Breastfeeding support group. Go with her if you can. They will support her to breastfeed, to mix feed and also to make the switch to formula if that's what she wants to do. You could also give her the numbers for the breastfeeding helplines (The Breastfeeding Network on 0300 100 0210, the NCT on 0300 330 0771 or La Leche League on 0845 120 2918). Finally, a post on the bf'ing and bottle-feeding section of this site would be a good idea. I have had AMAZING support there.
In the interim before the White noise CDs arrive (well you can download them from iTunes but anyway), the Hoover or hairdryer on full work really well. Second the suggestion of a good sling - perhaps a stretchy wrap like Moby or one that I got on better with, the Wilkinet. You can pick both up cheaply on eBay.
Do keep reminding her that it does end. If she can get out in the day that will really help. Any of the children's centre groups are great. Check out if the NCT run a post-natal course in your area. I went to one, once a week for six weeks and it was a god send. It's a facilitated discussion group with an experienced mum that covers everything from colic to sleep AND they give you tea and biscuits. You can find NCT course here: nct.org.uk/courses.
Lastly, I haven't been to one myself but the other day I came across something called BabyCalm (www.babycalm.co.uk/) that might be worth checking out.
Ooh, and really last, there's a video on YouTube of a guy called Dr Harvey Karp appearing on the Richard and Judy show that's worth a google. He has this technique for soothing babies involve swaddling, White noise and jiggling that's quite good.
Right, I think I'm done but I'll probably be back in a few minutes with another idea 