deferring a primary school child due to age

My daughter was just accepted to an ESF primary school after 2 years at ESF kindergarten. She was born on Dec. 28 and the classes at ESF cut off at Dec. 31 so she is the youngest in her class. We've always raised concerns about her age and pushed hard for her to start K1 the following year (most of her friends are younger), but rules are rules. Anyway, here we are again. It turns out the primary school principal had wrote a question mark next to her date of birth and had wondered if she was too young. however, the school accepted her. the primary school is giving us 2 weeks to decide if we want to defer her P1 admission until next year. The issues are 1) her current kindy has no openings in K2 for her next year 2) all her peers will be moving on to the primary school 3) her only option for next year is at Sunshine House where the school "might" be starting a pre-primary class- however, the class start depends on kids enrolled and there's a chance that it might be taught in mandarin if that is the majority preference of the parents. My husband and I have no idea what to do. We don't want her to always be catching up to her peers year to year- we want it to be relatively easy for her. However, i feel bad that all her friends will move on and I am a bit wary about her deferral getting lost by next year- based on previous experience, this primary school does not have great communication between the top people. Any advice?