People often think Lord Hanuman being a brahmachaari meant that Goddess Parvati, Lord Shiva's divine consort, was not present in his incarnation, but that is false.
My mother, who reads various scriptures to expand her knowledge, came upon this story in one of the epics, I think Devi Bhagavatam or Shiva Purana, I am not sure which one.
When Lord Shiva granted Anjana and Kesari a boon that he would be born as their son, he prepared to incarnate on Earth as a vaanar. Goddess Parvati asked him which form she should take, and whose house she should be born in, to unite with him in that incarnation. Lord Shiva told her that Hanuman would be a brahmachaari, so there was no need for her to incarnate with him, but Mata Gauri said that whenever he incarnates on Earth, she will follow in some form or other.
So Mata Parvati took the form of Hanuman's tail and stayed with him throughout his incarnation.
Realize the significance of Hanuman's tail in Ramayana.
Ravan insults Hanuman in the royal court and attempts to kill him, and as retribution, Parvati causes destruction on Lanka by setting fire to it.
It is Hanuman's tail that is used to kill various asuras and rakshasas who attack Ram and Lakshman.
The tail is Hanuman's shakti, because it is a form of Goddess Adishakti herself.
Thus, Goddess Parvati was able to follow her Lord and be with him wherever he went, and she aided in the purpose of his incarnation.