Hello, I ever got a Non-O visa from Vientiane a few years ago, 

I am father of a Thai Child daughter 4 years old, which is living with me only, her mother doesn't care about she, ( other story )

but I am not legal father, and not married to her mother.

Is it a good idea to bring her to the Embassy or Consulate applying for the visa ?

so, which Emb/Consulate actually deliver a visa Non-O just being  a unlegal father..

 

I have the original of the Birth Certificate of my daughter.. 

and some copy of tabiaan ban of her mother but not signed.. 

You can easily get a single entry non 'O' visa from Vientiane or Savannakhet, Laos and Penang Malaysia to name three.

 

No need or benefit in taking her with you when you apply. The original and copy of her birth certificate and a copy (unsigned) of her Tabien Bann is all that's needed.