Ælfswiþ

Elswida, Elswide, Elswith, Elswitha, Elfeswida, Elfswith, Elfswythe and Elfswitha are possible younger forms. A lot of these were based on this source:
https://www.s-gabriel.org/names/marieke/anglosaxonfem/ (See the heading "Ælfswith")

---

Alswyth and Alsueta are other forms. Source: https://heraldry.sca.org/names/reaneyAG.html

---

Alfswith could be another form. Source: https://anglisc.miraheze.org/wiki/Anglish_Given_Names [See Anglo-Saxon Names category]