so glad to hear she is playing and wagging her tail
a thought did occur to me on waking this morn, about her jags and the parvo test. your jags must be different from ours as we only give a pup 2 jags and then one a year after that but you said you give 4 to a pup, 2 things spring to mind, first is (over here) if the dog has sickness and or diahreoa soon after the jag it cancel that jag out, secondly, if the dog has been recently jagged against parvo it may show a positive reading in the blood test even if that is not what is making the dog ill, as most vaccines are actually a small dose of the virus etc.
your cousin will be able to advise you better on these things, you are so lucky to have a vet tech on hand
please keep us updated on this? things like when she's had her blood tane for the test, how long the results will take to come back, if they release her again after taking the blood.
if she is playing and wagging her tail then she is either very strong or it may just have been a seriously upset stomach
the thing about bloody diahreoa is that it is not usually as bad as we think it is, in most cases the blood is only coming from a very small popped blood vessel in the anal passage. as humans we know when we are empty and stop pushing/straining, dogs don't, they continue to push/strain even when they are empty and it's this unnecessary pushing that pops the blood vessel, it really is quite harmless. again your cousin is the best person to explain this properly i am just trying to put yours and your mother's mind at ease a wee bit.
still sending best wishes and anxtiously awaiting news