For the best chance of success, fetal matter should be at least 8 weeks of gestation. Due to the possibility that the mother's DNA could be mixed with that of the fetal matter, a known sample from the mother (eg cheek swab, blood sample) should also be tested. This sample will be used to confirm that the DNA profile obtained is not from the mother.

Yes, it is possible.  The historical success rate is 80%, but storage conditions and the age of sample can affect success rate.

Bode Cellmark prefers to work with items that are at least 3mm x 3mm, but may be able to produce a DNA profile from smaller areas, depending on type and concentration of the stain (semen, blood, saliva, etc.). Typically, a semen or blood stain yields the most DNA.