My son has dyspraxia and I can vouch for the poor memory. However, it isn't all types of memory - he remembers facts and figures very well. It is more working or procedural memory. He can't remember how to do certain things unless he has done them many times before. He also can't hold onto long strings of instructions. If I tell him to get his coat and shoes, pack his school bag and brush his teeth, he would probably get his coat and one shoe and then lose the thread. It can be immensely frustrating for both of us so I have to bite my tongue on occasion and remember he isn't being deliberately difficult. The upshot is that he is very badly organised. He couldn't cope without other people reminding him to do things. Like forevervacuuming he has no sense of time. Every morning I send him off to school, tell him to hurry or he will be late and he hurries for about 2 paces and then slows down again. I would agree that cutting some slack on time keeping is useful.
The other thing is that he finds large groups and new places confusing. From a sensory point of view it all gets a bit overwhelming. He doesn't have much of a sense of direction and if his way is blocked by, say, a group of people, he will plough on through the middle and then he appears rude. Being blocked by something more substantial makes him panic even if there is a way of getting round it if he would just look.
He can't see things that are in front of him and can never find anything, nor does he have the strategies for dealing with this. He can't retrace his steps or remember where he last saw the item.
Actually I got a really good book last Christmas - Caged in Chaos. It is aimed at teenagers so the bits about school will not be relevant but it is a very good description about what it is like to dyspraxic, and it is very readable. I noticed whilst getting the link that the author has also written a book for adults here. It seems to get mixed reviews but it might be worth a look.
I don't know if the others on this thread who have the condition would agree, but I have assumed that by the time my DS has got to adulthood, he will have developed coping strategies for most aspects of life. I hope so anyway. I would assume that your friend has them too - she seems to from what you have said.
I think the only thing you can do without making your friend feel inadequate is to be understanding which is exactly what you are being. Cut her some slack if she needs it and let her know you are there to help if she needs it. She is lucky to have a friend who cares so much. 