I can sympathize with you, as I am a very competitive person--I will compete with others and I will compete with myself...BUT, that being said, you have to learn to turn it off and sit back and enjoy her company. She wants to share in something that you enjoy---that is wonderful. You will have plenty of other times to ride fast...but how many times do you have to share that riding ewxperience with your wife? Mine does not ride---and I wish she did.
Tim C.