Sulis the Goddess associated with the Hot Springs at the City of Bath before the Roman occupation who named it Aqua Sulis.
Solar goddess
Based on her name's etymology, as well as several other characteristics, such as the association with sight, civic law, and epithets relating to light, Sulis has been interpreted as a solar deity, at least in pre-Roman times. Some researchers have further suggested a role as the de facto Celtic solar deity, the associated Sulevia and similar names being the goddess's attestations elsewhere. Wiki Sulis
Sulevia
Latin name given to a triad of mother-goddesses known in many parts of the Roman-occupied Celtic world as well as in Rome itself. Iconographic and epigraphical evidence suggests that the goddesses were linked to cults of healing, regeneration, fertility, and maternity. They were worshipped at three sites in Britain: Colchester, Cirencester, and Bath. This latter site suggests a connection with Minerva, one of whose epithets is Sulevia, pl. Suleviae. See also MATRES
https://www.oxfordreference.com/view/10.1093/oi/authority.20110803100541483
Triple Deity - Ancient Celtic cultures
MATRES . The matres or matrae ("mothers"), Celtic feminine divinities, are attested throughout the ancient continental and insular Celtic domain (with the exception of non-romanized Ireland) by abundant Romano-British and Gallo-Roman epigraphic and iconographic testimony. The word is Latin, but it can only be the translation or adaptation of a Celtic word, as the Gaulish inscription at Nimes consecrated to the matrevo namausikavo ("Nimesian mothers") witnesses. On the evidence, the matres as a group are very diverse, and it would be difficult to propose a single explanation for them. A matre may be conceived in terms of a particular locale, a certain function, or a principle and sphere of sovereignty. Specific instances are frequently multiple: the Suleviae, solar goddesses who have been unduly transformed into psychopomps; the Iunones, who are multiple forms of the Latin goddess Juno; the simple Triviae or Quadruviae, who watch over crossroads (but may not be truly Celtic).
Thus the term matres has come to designate several types of feminine divinities who are in some instances anything but mother goddesses or protectors of fecundity. At first, prior to the identifications and multiplications, there was certainly a single feminine divinity. Described briefly by Caesar under the name of Minerva in his account of Gaulish religion, she is at once mother, spouse, sister, and daughter of the gods.
In Irish Myth
This unique goddess in multiple form may be identified, in the context of Irish myth, with a range of feminine deities. There is Brighid, daughter of Daghdha, but also mother of the gods and protector of leeches, poets, and smiths. There is Boann, who is wife to Elcmhaire but bears a son to Daghdha. Also, and preeminently, there is Édaín, sovereign and ancestor of a long line of Irish kings. Further, there is Morríghan ("the great queen"), goddess of war and wife of Daghdha, she who washes the bloody remains of heroes who have died in combat. There is Macha ("plain" or "level land"), eponym of Emhain Mhacha, capital of Ulster. There is the gentle Fann ("swallow"), wife of the god Manannán, who loves and tempts Cú Chulainn, and there is Tailtiu ("earth"), foster mother of Lugh. Finally, there are the allegorical personifications of Ireland and queens of the Tuatha Dé Danann: Ériu, Banbha, and Fódla.
https://www.encyclopedia.com/environment/encyclopedias-almanacs-transcripts-and-maps/matres