Is there Solar Eclipse in Terraria Mobile 1.2?
Yes, the Solar Eclipse is there.
The Solar Eclipse was introduced in the PC 1.2 update.
If we take a look at the Mobile Version History, we can see the latest update:
1.2 Update
(1.2.1 PC equivalent)
Since it is equivelant to the PC 1.2.1 patch, that means that the Solar Eclipse has been added.