Hi sarah
Special tests for biceps are speed's test and yergasons test - they'll be easy enough to find online or in brukner and kahn. try them and take them on board with other tests. our 'special tests' are never as specific or as accurate as we'd like them to be.
Definately a good idea to check her technique with swimming - or it may be that she needs to slow it down and build up her stength again before returning to swimming (this is assuming she tried to return to pre levels of activity too quickly). Let us know how you get on.