What punishment should I recommend for Soldier who showed up for an ASU inspection with it on a hanger?

Just push and push and more push.

She should have been responsible enough to purchase a new uniform that fit. I gained weight after basic. I purchased another uniform that fit. I kept both uniforms to ensure I always had a uniform that fit. She absolutely deserves corrective action (Punishment). It's up to you what punishment, but she showed irresponsibility as well as not being in uniform.

Corrective training/remedial action. I don’t know why people have just plain “lost” the ability to communicate deficiencies. Was she too embarrassed to say anything that she had a little too heavy for the uniform? She couldn’t get a new one? So what’s her financial situation that she couldn’t afford to get new ASU’s, since the Army gives us money to replace our outgrown/unserviceable uniforms? Your/our jobs as leaders is to help guide and teach those underneath our leadership. Not punish and smash them into smithereens. But on the other hand, I don’t believe in always counseling for remedial action. Sometimes a good scuffing is all soldiers need.

Where do you start. Wow has the military changed that much that one could even get away with this no less to say that takes a lot of lack of planning on her behalf.
First off she needs to be told that this is not acceptable at all and for her to get her stuff together and report back to this duty station at this time and date.
This will be the last warning and the next time you will be written up and the proper punishment will be applied.

You're a SSG. Figure it out.

Counseling works better than punishment. Punishment leads to more negative behaviors. I always punished as a last resort. For her, she needs to be placed on the overweight program if it is deemed that she is? Or give a timeframe to adjust the uniform and schedule another one-on-one inspection?

Remedial PT in the form of all her uniforms on hangers that she currently isn't supposed to be wearing, then rolled up in a rucksack that she has to carry everywhere except to sleep, with a 25lb weight. Several times per day she will run a lap around the brigade space within a time limit that she and I determine running together once when she is rested so that I know she isn't walking instead of running.

This ends when the uniform fits again.

;)

As the SFC stated she failed, dig to the root cause and if she does not correct escalate to command authority for possible UCMJ action

The inspection should count as a failure and she should have to endure the consequences normally associated with a failed inspection. After that, if she is a good troop, find out why she chose her path and offer her some help with her weight problem and the underlying causes. If she isn't a good troop and has been a habitual PITA, process her for failure to maintain standards.

Hmmmmmm this may sound stupid but did you tell the soldier that she need to wear it for the inspection. I say this because these kids you havr to ber very descriptive and exacting with them. They will just act like they are smarter than you. Secondly, You cannot punish anyone, The commanding officer is the only one that can do that. You can only enforce the punisment given by the CO. Thirdly why wasnt she sent to the Doc's fr weigh in and taped whe you noticed her excessive weight gain, Part of a good leadership is intrusive leadership. Not only is it a requirement for her physically wise but also medially wise. This is called taking care or your soldiers , sailors, Airmen and Marines. I can go all day about this, so this is the condense version. These kids need to be p4repared for battle, She cant carry a 75 pound ruck sack if she cant manage her weight, Good luck, Oh and BTW annotatre everything and evaluate her with integrity.