… I though it was only in cases of canonical consecration by a Bishop that The Church formally received the vows and dispensation would be required, hence, from Rome. Where the vows are private and received by a priest, I had thought, then the priest could dispense.
Here I just strongly recommend seeking guidance from the diocesan bishop and offer some thoughts.
There is a difference betwen vows that result in membership in an institute of consecrated life and those by which a person individually assumes as an obligation freely made to God without conveying any juridic bond to an institute. The former are accepted in the name of the Church, and the latter are simply declared. They are not per se received.
Secular institutes (and religious institutes) are forms of consecrated life. In these cases, dispensation from the vows or other bonds of permanent or definitive profession is referred to the Holy See. Such vows or other bonds establish one as a member of the institute.
By contrast, private vows do not create such membership in an institute, and thus, they can be dispensed or commuted even by the local pastor, and often other priests such parochial vicars have the faculty to do so by delegation.
The title of “sister” and religious habit are usually associated with profession in an institute of consecrated life, and possible the kind of association of the faithful mentioned below (*). Religious habit is a particular sign of consecrated life and of poverty in connection with membership in such an institute. Those signs are in witness of both. (On titles and attire. One is a “brother” or “sister” relative to the other members of the institute. Those terms are not expressions of generic relationship to all Catholics, and thus are usually not assumed in the case of private vows. Similarly, religious habit has a collective rather than an individual quality to it.)
Unless there is membership in an institute of consecrated life, vows of poverty and obedience become somewhat problemmatic. In consecrated life, one assumes poverty, turns over the fruits of one’s work to the institute, and the institute assumes the duty to provide for the member. The obedience involves particular obedience to the superiors of the community. This effects things such as place of residence, life style, forms of prayer, apostolic works. But though problemmatic, possibly not unsolvable, I might think. However, a private vow of perfect continence for the sake of the kingdom could be observed by anyone.
If it is a matter of seeking to enter the order of virgins, that is a different matter. That life is similar to, but not the same as, consecrated life. There are provisions in the liturgical rites of the Church for that.
(*)Private vows may however be connected to membership in a public association of the faithful which is seeking to become an institute of consecrated life, and there one would look to the statutes for guidance. But I do not believe this is the situation that has been presented.
Again, I counsel reliance on the diocesan bishop. He has access to, and can consult, his canonists or the Holy See.