Is married certificate enough?

Hi guys, I hope someone can help me.

We are a Brazilian family applying for a tier 2 visa from Poland.

We have been living together since 2012, but we got married in December 2017, but we have two children (5 and 3 years old).

I have been living in Poland since September 2018 and due to the school year in Brazil ending in November my family joined me in November 2018 and we have been living together ever since.

So we went to Brazil in August this year on vacation, my wife and children are still there on vacation and they will return to Poland this weekend. We plan to apply for this visa all together on October 2.

Would it be a problem with the home office? I mean, should I include whatsapp messages or anything else to prove we're still in touch and living as a couple? Or in this case should the marriage certificate suffice?

Many thanks