Single mother introducing 5 year old to new partner

Hi Sara, I'm so glad I found your website! I had alot of unanswered questions and your article about children & a new partner gave me comfort. I need some advice on how a 5 year-old can accept someone else in place of their father. Although she isn't attached to her father she might be jealous but then again its not the right time to introduce anything at the moment right?? I just need some brief advice, anything will do :) Thx for your time, appreciate it!