What are Good rates to charge for portfolio development?

Learn and know your day rate.  Then charge what you need to charge to cover the bills and make what ever profit margin you have built into it.  If it's something that will be mutually beneficial, shoot TFCD.

-Major

Portfolio development sounds like TFP to me

You have a couple of cute, well done shots in your port, but mostly your shots look sort of amature. I would stick with TFCD for a bit if I were you.

Charge what the pictures are worth.

I know, that sounds like useless information, but bear with me.

If you can produce pictures that meet professional standards, are in style and of the quality that models can use to get hired, then they are of value to models.  The value comes from the fact that they can help her generate income as a model.

Pictures that do not meet the expectations of paying clients are not worth paying for.

If your pictures are of fashion-magazine quality and style, you can charge several hundreds of dollars for test shoots.

If your pictures are excellent lifestyle images, you can even charge more than fashion photographers, because few good lifestyle photographers do test shoots.

How to tell if you are in either of those categories?  Go to real, booking agencies and ask them if you can be on their test list.  They will let you know very quickly.  If they say no, you probably shouldn't be charging for fashion and commercial models, because your pictures will do them no professional good.

If you can do excellent glamour or art pictures, you can ask to get paid, although at lower rates than for fashion test shots.  And your chances of actually getting paid aren't all that great, since models can usually find good glamour and art photographers willing to shoot them for free, or to pay them.

Good luck with it.