No personal assistant will come get you at your AC gate - they start caring for you once you arrive at LH's First Class check-in (ln/a in your case as you will be checked through).
Either way, if you arrive 9h (!) before your LH departure at ORD, I'd be surprised to find any LH staff already on duty at all. I'd go into town rather than hang around the UA F lounge for this long.