Catimini for the coming baby

My sister will be having her baby shower next month and I am still confused what to buy for her that is very useful when the baby come. She will be having a baby boy and we are all excited to see him soon. My husband suggested that it would be better if we give my sister a catimini onesie sleeper for the baby since he will be born during the winter time. So having this very comfy onesie sleeper could would be the perfect for him to protect him from the cold weather.