1.) If you're mother does not have any cardiovascular co- morbidities then Ecosprin is likely to be disconnected after 3-6 months depending on her lab report. It may very from patient to patient. 2.) Since there are multiple strains of the virus, one has to be precautions even after infection, as the patient might have antibodies for certain period of time but ONLY for that particular strain. 3.) Fungal infections are rare in immune competent patients. If your mother doesn't have immunocompromising disease, for example diabetes etc. or is not on steroids then the chances of her having fungal infection is quite less.

Yes every person who are recovered from any infectious condition will develop antibodies against the same. However it depends on what type of infection and titre of antibodies developed against it. Talking about SARS-COV-2 infection, according to various case based studies the antibodies developed by body's response will remain atleast for around 90 days and more, though it's titre varies but once immune system have memory of antibody against any antigen then our body is capable to increase it's production when source of infection reappear.