have you weighed your little spikey baby ? it's weight is a reasonably good indicator of age.
some comments :
>>> the basking light ? …. is it an MVB ? what brand ?
>>> if it's not an MVB , what are you using to provide UVA and UVB ?
>>> see this for a guide :
viewtopic.php?f=34&t=235611
Key points :
UVA & UVB at very high levels is MANDATORY for a bearded dragon.
UV source should be positioned UNDER the mesh lid, a fine mesh lid like you have will block more than 45% of the UV.
Aim for 200 microW UVB / sq.cm at the basking spot.
Aim for 1000 microW UVA / sq.cm at the basking spot.
At least 14-15 hours per day photoperiod.
>>> temperatures , no hotter than 40degC at the basking spot.
I see you have a dial type thermometer , theres are worthlessly inaccurate , better off tossing it inn the bin and buying a brace of these
https://www.ebay.com.au/itm/2-LCD-Digital-Temperature-Thermometer-Fridge-Freezer-Aquarium-Fish-Tank-Reptile-/222959498797?oid=391259141696