Full Name Desired

We have found the name Sunneva - <Sunneva> is documented from "Jensen's Scandinavian Personal Names in Lincolnshire and Yorkshire" (pp. 271 - 272) sn. Sunnifa. Commentary pointed out that per the google books preview of FJ, <Sunneva> appears in the Latin ablative, 1121-27; based on this it is after the cutoff for mixing Scandinavian and English.

Niva is found as a period masculine name in Russian (нива), although it's a feminine word ('cornfield'). You can combine Russian and Norse. You might have to use the masculine form of in rauða (which is inn rauði) to make the name consistent for gender. Rebecca Le Get might be able to support a feminine Niva/нива, which would get you Niva in rauða, but Niva inn rauði should be registerable. http://heraldry.sca.org/names/paul/n.html

Byname/Surname

In Rauda - ‘inn rauði’ as an adjectival byname meaning "red" on page 26 of Geirr Bassi's The Old Norse Name shows. This has been modified to the appropriate feminine form following the rules given on page 19 of The Old Norse Name.
hin Rauða - is the feminine form of <hinn Rauði>, a descriptive byname meaning 'the Red,' from The Bynames of the Viking Age Runic Inscriptions by Lindorm Eriksson; https://www.s-gabriel.org/names/lindorm/runicbynames/body.htm#start, originally published in KWHSS Proceedings 1999. Also found in FJ, p. 216.