Does it sound natural On Sunday we had Easter.
We went to a vigil service which started at 11 PM and finished at 4 am.
We made special.pastry and dyed boiled eggs in red.
I.put on weight since my pregnancy. I must shed more than ten kilos but I am afraid to go on a diet as it can reduce my breast milk.

Question

Does it sound natural On Sunday we had Easter.
We went to a vigil service which started at 11 PM and finished at 4 am. 
We made special.pastry and dyed boiled eggs in red. 
I.put on weight since my pregnancy. I must shed more than ten kilos but I am afraid to go on a  diet as it can reduce my breast milk.

Answer

It is fine.  You might also say "On Sunday, we celebrated Easter."

Happy Easter!  Christ is risen!

Answer

Well done. :)
It is not quite 100% natural though. I have made a few (small) corrections below.
You can say "Easter was on Sunday" or "On Sunday we celebrated Easter".
"We made a special pastry and dyed boiled eggs red." (no need to write "in")
" I have put on weight since my pregnancy" ("Have" for past tense)
"I must lose more than 10 kilos... " ("Lose" is the idiomatic word in English for decreasing weight)
"... could reduce ... "
Happy Easter! :)

Đừng bỏ lỡ cơ hội học ngoại ngữ ngay tại nhà. Hãy xem danh sách các gia sư ngôn ngữ giàu kinh nghiệm của chúng tôi và đăng ký buổi học đầu tiên ngay hôm nay!