As nouns the difference between mother and doula
is that
mother is a (human) female who (a) s a child (b) gives birth to a baby (c) donates a fertilized egg or (d) donates a body cell which has resulted in a clone sometimes used in reference to a pregnant female, possibly as a shortened form of mother-to-be or
mother can be something that is the greatest or most significant of its kind or
mother can be (euphemistic|coarse|slang) motherfucker or
mother can be (nonstandard) a cat that catches moths while
doula is a support person, usually female, who may not have medical or midwifery training, who provides emotional and practical assistance to a mother or pregnant couple before, during or after childbirth.
As a verb mother
is to treat as a mother would be expected to treat her child; to nurture.