'Menace II Society' Samuel Monroe Jr.'s Wife Blasts His Mom Over Conservatorship Bid

The wife of actor Samuel Monroe Jr. is livid that his mother is apparently trying to get the court to cut her out of the picture while he's debilitated in the hospital ... and she says she's ready to go to war.

Shawna Stewart tells TMZ she believes Joyce Patton's petition asking to establish a conservatorship for her son is financially motivated -- and not about Sam's well-being.

The actor's wife says Sam made it clear he wanted her in charge of his money and medical decisions ... and not his mother.

As for Joyce questioning whether the couple is legally married ... Shawna won't share proof with TMZ -- but says his mom is in for a surprise.

According to court docs obtained by TMZ, an attorney has been appointed to the case on Sam's behalf ... and his medical records were ordered to be released to a probate investigator assigned to the case.

In her petition to the court ... Joyce mentioned the GoFundMe set up by Shawna for his bills ... and said she believes Shawna is receiving his film residuals.

Shawna tells TMZ she's not touched a penny of Sam's money -- and suspects his mother wants access to funds -- hence, the conservatorship bid.

Shawna also says Joyce's claim that she and Sam have not lived together in 15 years is BS ... telling us they have two children together, have been on and off again for the past few years, and have lived together during some of those stints.

The actor, best known for his work in "Menace II Society," has been hospitalized since April ... initially going in for a severe case of meningitis, which turned into MRSA pneumonia -- and from there, it seems one severe medical issue after another has piled up.

We'll see how this all plays out.