Qualities of a lady who can be a Guru
sadhvee - virtuous
sadaachaara - well conducted
gurubhaktaa - worshipful of own guru
jitendriya - one who has conquered the senses
sarva mantrartha tatvajna - knowledgeable in meaning and tatva of mantras
susheelaa - affable
poojane rataa - engaged in pooja
sarvalakshana sampanna - endowed with noble signs and attributes
jaapika - engaged in chanting of mantras
padmalochana - one with eyes like lotus petal
ratnalankara samyukta - adorning gems
varnabharana bhooshita - adorning colorful ornaments
shaanta - peaceful
kuleena - of high descent
kulajaa - born in good family
chandrasya - having a moon like face
sarvavrudhiga - having all types of prosperity
anantagunasampanna - having endless virtues
rudratvadayinee - capable of conferring rudratva]
gururoopa - having the form of a guru
muktidatree - capable of giving salvation
sivajnananiroopinee - engaged in understanding sivajnana
Mantra deeksha should not be received from a widow. If the widow has a son then she can be a guru. If the mantra is of the nature of sidha mantra for the particular sadhaka, then it can be received even from a widow (having a son).
Deeksha received from a lady guru is eight times more powerful. The essential condition is that the guru should be putravatee (having son).
If deeksha is received from one's own mother, that is capable of conferring all the eight sidhis to the sadhaka.
If the sadhaka has received mantra deeksha from his own mother in dream, then he should not receive deeksha from anybody else.