Sensory Processing Disorder won't go away or "get better." What gets better, hopefully and in theory, is a person's coping skills. That's where therapy comes in (not maturity). That's where preventative techniques from mom and dad come in.
My middle daughter has SPD, and she definitely has issues with certain noises and loud noises. We get her soft foam ear plugs, and she likes that they're comfortable and colorful.
She has problems with certain textures, flavors, odors, and is also very sensitive to visual stimuli. She engages in sensory-seeking behaviors too. We could tell at birth that she had some sensory issues... she's ten now. She's handling some things better but other things are worse. There are new issues all the time.
An OT is definitely a good idea. I would recommend having a sensory kit for her at home and one that you can travel with. I would also have an exit plan for her that she can rely on when things become overwhelming. She would probably do well having a script ahead of time of how you expect things will be, and if things change as you go you can adjust the script for her. That will help her cope.