This would be a neonate (baby) Crotalus Horridus (Timber/Canebrake rattler). As long as she and the dogs do not mess with them and give them the space a venomous snake needs, they shouldn't pose a problem. Knowing that there are rattlers there, use EXTREME caution when outside.
My friends and I collection: Venomous
Agkistrodon C. Contortrix x2
Agkistrodon P. Piscivorus
Crotalus Horridus
Sistrurus Miliairius Miliairius Colubrids
Lampropeltis G. Californiae x3
Pituophis Melanoleucus Sayi
Lampropeltis Triangulum ssp. Boas
Corallus Hortulanus x4
Boa Constrictor Imperator x2 Pythons
Python Regius x2