Debra, I do have a suggestion. .... Keep your doubts to yourself. Let your friend decide. Don't front-load her with doubts.
Be confident of your incredible talent and ability and just fricken ship it to her. It is a beautiful portrait. Try just keeping quiet. I guarantee that she will have her own opinion that you can deal with later and you are very capable of dealing with any changes - if any. If you give her YOUR doubts, SHE will have too much information that she doesn't have the ability that you have to deal with.
Your friend,
Anna Freud...AKA Carol Norton