It's not clear from your post exactly what is going on, with this rotation of tenants. Should we be inferring that this is a continuing lease, but with three substitutions of tenant due to former tenants moving out and new tenants moving in and being substituted onto the lease?
Breaking your lease over seeing five or ten spiders per day? Unless they're poisonous along the lines of brown recluse or black widow spiders, not a chance.
If your roommate / co-tenant is responsible for the infestation due to her cluttering up the garage and creating a spider habitat, be aware that the landlord can charge you (the tenants, collectively) for the cost of extermination.

