I also agree with Norma, this lady is not a genuine friend, and is one you can do without, she is saying these things to provoke a response, I can understand the question where she asked if you were doing it to make you feel good or for your daughter, but no genuine friend would ever say that, it's totally inappropriate, and if she was a real caring friend she wouldn't even need to ask that, indeed it would never come into their head to do so, her husband sounds little better.
This lady friend is what I call a "Put Downer" friends like this are not worth having, instead of showing real empathy and support especially at a time when you need it, they tend to undermine you.
Your rather vulnerable at the moment, also because of your loss it's probably discussed frequently and it's likely the subject of your daughter will be at the forefront of your mind which is natural, I talk a lot about my wife who I lost in April after 49yrs marriage to un-diagnosed cancer, but others often don't share your grief, they have no idea at all how you are really feeling.
My son said he stopped grieving at his Mums funeral, and indeed said to me about 2 months ago 'Dad she's dead...let her go and stop talking about it' he thinks I'm full of negativity all the time, IOW he's a prat and couldn't care less. My daughter is the opposite, she lives furthest away 235miles but phones every day and is staying with me next week, the 3rd time since her Mum died.
Fortunately there are people who genuinely care and are supportive, and sadly there are those that in reality don't really want to know if the truth be told. IOW the opposite, and these sort of people instead of being genuinely supportive at a time you need it, actually enjoy pulling you down, or at least it would appear that way sometimes, it's even possible your so called friend may even be a little envious of the attention you have been receiving because of your loss, I know that sounds totally crazy, but we just don't know. You know yourself this friend is not helping you, she gets off on knocking you down,...you don't need it.
Julie's more tactful thoughtful reply may also be a option if you wish to remain friends with her, but I have a feeling she would not respond in a positive supportive manner, I hope I'm wrong, and to quote Julie...It is a difficult one.