You are right , female sounding does not get as much attention as male sounding. I have experience in sounding personally and have sounded several females.
I think concerns about UTI's is a factor in deterring some women from engaging in sounding. Also it's a little more difficult to do by yourself as a beginner. Like anal there is some discomfort that goes with sounding. There should NOT be any significant levels of out right pain. Pain means you are not lubing enough, or pushing to hard on a sound that may be to large for your urethra. Sounding is not a race to the finish . It is an acquired taste that you develop over time. Sounding is a pleasure that you can enjoy your entire life.
A female actually has more useful anatomical parts than a male which all can be stimulated simultaneously. The hub is the urethra and bladder, then add the clit, vagina, lips and groin and the anus. Any or all of these may be stimulated while sounding the urethra and bladder. Remember your urethra is short( about 2-3 inches depending on how big you are). A male urethra is about 6-10 inches.
Try to start with a 5-7mm ( 16fr. - 22fr.) sound. Pratt sounds made of stainless steel are good to purchase as their tip is narrower and tapered longer tan other sounds. It also good to invest in a second set of short one end flattened Hegar 8'' long sounds. These have a rounded more blunt tip. Sounding can get addictive and you may want to enlarge you pee hole to 12-14mm or more. If you are into Med-Fet then sounding fits right in. Also many female use a speculum in the beginning . Some stay with it every time ,others get more experienced and don't use it. Vibraters, dildos,string, clothes pins, needles, and electrodes( The sound can become an electrode) are a few additions that can be made to a sounding session. Electo - stim with an Sextek 312B power box is wild. You will be back for more.
Learning how to prep yourself for sounding is a must ,as is sterilization of the sound(s). You should read up on technique and prep for female catheterization. Also purchase of catheter insertion kit could be helpful in the beginning. While talking about catheters ,have you been cathed with a foley cath connected to a drain bag? Med-Fet
Ask any question you like , I will attempt to answer it or some else may chime in also. Go for It.