Be there for your friend, don't discuss your own business as it can sound as though you have gone there before her (which I realise you have, but she won't want to hear that). Sympathise without being judgemental and be there for her if she needs to pour her heart out to someone. Also, don't make any remarks about her husband, they might just get back together sometime in the future and she could remember what you had said about him at this time. Only writing this from having been through the same thing myself.