How do I network 2 home computers & 2 identical hp psc printers, each printer to print from its own computer?

I am adding my daughter's computer and printer to her bedroom. I installed a router and cable connecting from my cable modem to both of our computers and have operational e-mail and internet access. My computer prints, as usual, from my computer on my hp psc 1200 series printer. My daughter has a Dell computer and also a hp psc 1200 series printer. Her printer works fine for copies and when I first installed it, also printed from her computer. Now I can't make either printer work from her computer. I've checked the USB connection from the printer to her computer and it seems to be OK. In the Control Panel/Printer & Fax list, my comuter shows my hp psc 1200 series printer and also an Auto hp psc 1200 series on CINDY-A4CO4MMAO, which I think is the number of her computer. That option doesn't appear on her list of printers. I think I need guidance. I am a 79 year old lady who is reasonably good with my computer but not knowldgable about hardware or networks. Thanks for any help.