its safer before heat, so i would go with asap, ive had chis come into heat ON that 6mth mark, others not untill there closer to a year...so its difficult, if you want to be sure and miss that heat now would be the best...
vixie was spayed at 2 yrs but thats because she was a show girl and bred, difficulties required spay.
i prefer "pets" be done at 6 months. but 6-8months is the common recomendation of our vet for toy breeds!
and welcome aboard Ruby