Wife gets mad so easily?

My wife gets so mad so easily. We have been married for about 15 months. We also have purchased our first home and had a baby in these 15 months which is stressful. but say for instance, she calls while i am at work to tell me that she is worn out and the baby will not go to bed. She does have a bad cold right now but I am at work 40 miles from home. I just suggest using pacifier, bouncer, etc and she just goes off on me which is normal. mostly while i am at work. THen I get upset with her and that doesn't help the situation. What can we do. I think I help out with the baby as often as possible. I know it is hard raising a little one especially in the evening while i am gone. but i do all that i can while i am there( feed, change diaper, play. etc...)