When to announce to family only

Misty

Hey guys I’m almost five weeks pregnant which I know is early. Here is our situation. After three years of trying for a second baby and after two rounds on fertility meds I’m pregnant! We have told my older child who turns 4 tomorrow. She had a right in my opinion to know since she has been just as antsy as us. Well this weekend is her birthday party with lots of family! I’m pretty sure at some point she will slip up (I don’t expect her to keep it a secret) and tell everyone there. Should I just come out and tell my family? Is it too early and should I just try and monitor what she says?