Lildereth looks so at peace and like she belongs in that tall grass overlooking the IC! I'm guessing that is one of Maigrets' bats? She makes fabulous critter companion mods but, as you know, you have to find a place to tell them to wait, can summon them to you but can't unsummon them.
As you surmise, SubRosa's Witchcraft mod might be superb if you had the SI. Her summonables are available (once you learn the spells) for custom spellmaking at the altar. If you get the chance, SI is a great addition all on its own just for the wonderful exploration and change of pace from Cyrodiil.
Another possibility for a basic summon that is neither Daedra nor undead would be summon black bear. The effect is already in the game (for spriggans). It can be made available to players from a variety of mods (can't recall any specifically) and also via the Spell Tomes DLC.
At any rate, thanks for those fabulous shots of our sister mystic archer!