"dan" should be as correct as "serta". "juga" can also be used.
Can "Tini sama anak-anaknya" also be correct? Also, like, "Kamu pergi sama siapa?".
I guess itu kurang formal :/
Why would one need to translate this with the plural specifically, since we have noy been specifying the plural in so many other sentences?
It works without the explicit plural, too. Just checked.