Justin Bieber's Alleged Baby Mama Mariah Yeater -- My Baby Will Take The DNA Test

Mariah Yeater -- Justin Bieber's alleged baby mama -- will submit her baby for DNA testing ... this according to her legal team.

Attorney Jeffrey Leving tells TMZ ... his client is NOT avoiding the DNA test, and can't wait to compare baby Tristyn's DNA with Justin Bieber's.

But Leving says he DOES have a big problem with the DNA test Justin has already taken, because a member of Yeater's team was not present while it was administered and he has no idea if the test was done using proper controls.

Although members of Justin's team have told TMZ Yeater and her team had gone radio silent since Justin took the test on Friday, Leving says his co-counsel has been in touch with Justin's lawyer, Howard Weitzman, Monday and Tuesday. Leving says he hopes both sides will reach an agreement on a DNA protocol.