It is not normal for a normal to get a wobble.
The spider wobble is tied to just spiders and spider morphs.
When normals or other morphs that don't typically get a wobble have one, it means its probably an incubation or temperature error that caused a neurological issue. For example, a high temperature spike can cause neuro issues.
If the head shaking is new, could be dehydration. But since you say she eats well, I kind of doubt this.
If she's eating and healthy, then I wouldn't worry about it. I have a pin that wobbles slightly and is one of my best eaters as well.
His slight wobble(barely noticeable) is incubation related.
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