Will us be blood related, as she is from my uncle's wife's side and I am from my uncle's side?
This particular answer can help you.
Manusmriti 3:5. A woman who is not of the six generations of the mother and of the father's gotra is recommended to twice-born men for wedlock and conjugal union.
If it was the cousin-brother, As your uncle already married in that family, that means your Gotra is different from her gotra, It should not be a problem.
If it was a cousin-sister, better to check the gotra again, should not be an issue in that case either.
I hope you understand this difference. Anyways, better to consult some pundit for this.