Cpap Mask for baby

My daughter is 9 months old and was diagnosed at birth with Down syndrome. At 3 months old she was also diagnosed with sleep apnea. She has been using the fitlife full face mask extra small but it's now getting too small. The small size mask is huge on her. Can anyone advise an alternate? It's needs to be a mask that goes over both her mouth and nose as she tends to be a mouth breather. I will get maybe 4-6 weeks more out of the current mask. Any advice I would be grateful

http://www.cpapplus.com/pediatric-masks

Take a look - there are quite a few!