I want to be clear, I'm not wondering if she is an ideal support, .. obviously there are plenty of other supports that would be better, but in low level solo que, I think it is important to pick supports that are able to carry if they need to because it is not always reliable to count on your ADC to carry.
I am thinking she should start with Relic Shield. As a melee champion she can proc the execute, and with as good as she at killing minions and resetting her Bladesurge, I could see proccing a stack, or multiple stacks of Spoils of War, then jumping on an enemy for the engage.
Her W is good damage mitigation and her E and R are good crowd control on potentially multiple targets for all-ins or even tower dives.
I'm not sure how else would be best to build her.
She scales really well on both AD and AP, but I'm thinking AP is better for her.
As a melee support she does need to put some money into health and resistances, and possibly some other sustain as well.
I haven't tried it, but I'm wondering if someone else might have, .. or might be interested in trying it out.