I personally wouldn't worry about her weight as young as she is. As long as she is eating and being fed well it really does not matter. Some seem to grow super fast, some don't. Being she is not refusing meals she is going to grow at her own pace anyhow. I have 1.1 pastels that were clutch mates from around the same time that I haven't weighed, however they both started on frozen thawed, worked their way up to frozen thawed adult mice the female took 2 every time the male took 1 every time. The female is over double the size of her clutch mate brother. also the male just straight up stopped taking F/T and will only take live. LOL they seem to be more in control of their eating than I am.