Miss Muffet

Ok so my girl is a regular 6 month cycle. She came into season in April and was successfully bred on 30 April. Puppies arrived 1 July and were fully weaned at 6 weeks. Left for their new homes at the end of August. My girl has not come into season again yet. I thought she may do end of October ( 6 months after her last season) but after reading the comments I think im wrong. Anyone advise me of when her next season is likely to be please?