You may be looking for the character of the similar name, Altena.
About 780 years before the beginning of Fire Emblem: Path of Radiance, a great war was waged between the two goddesses of Tellius: Ashera and Yune. One of the strongest warriors under Ashera's command, Altina was chosen to lead the war against Yune, alongside Soan and Dheginsea. To compensate being the sole Beorc among the three and aid, Ashera blessed Altina's swords, which would be known as the most powerful swords in Tellius: The golden blade Ragnell and the silver sword Alondite. Together with Dheginsea and Soan, Yune's forces were defeated and the Goddess of Chaos was sealed into a medallion to prevent future wars while Ashera went into slumber, while Altina sought to achieve this on behalf of all beorc as promised by their pact.
Things were seemingly going as intended at first, as Altina founded Begnion to be a place where both laguz and beorc could co-exist, serving as it's first queen while marrying Lehran, eventually giving birth to a child, who they and their friends believed would become a symbol of peace between the two races, as laguz-beorc couples existed before, but conceiving a child together was unheard of at the time.
However, when Lehran lost all of his laguz abilities after the child was born, this news caused great turmoil among them, who believed that this development would harm relations between the two races, and could even have lead to the child's death. At Lehran's request, Altina covered the incident along with others, under the pretense of him having died in an accident, and denied any relations he had with the child. She then re-married and raised their child as a beorc born of her new husband.
Unbeknowst to them, Lehran's communion with the goddess would eventually resurface in Altina's granddaughter Yoram, granted by having his bloodline. Successfully predicting the coming of a great famine in Begnion, she was hailed for her ability to hear the voice of the goddess and became the first of Begnion's apostles, unaware of the true origins of this power, as it led to the reorganization of Begnion into an empire. It also caused to a rumor to spread that Altina is the only person capable of awakening Yune through the Galdr of Release. However, this is proven to be false, as the galdr can only be sung by the firstborn of each generation of her descendants. Such confusion likely came about due to Altina's own name becoming the surname of her lineage, although very few in Begnion were ever aware of this fact.
The name 'Altina' evokes the Latin verb alo alere alui altum ('altum' is the past participle) which as a verb means 'to grow, support, rear, feed' and as an adjectival participle (altus, a, um) it means "high" or "deep".