Slander by deeds

My wife petitioned her mother and came here to live with us. As days go by she started to be so annoying. She refuses to share chores or makisama. She has a known illness of diabetes, Hypertension and heart problem. She's constantly doing things that are harmful. such as eating sweet stuff or not eating at all. She came here weighing 120 lbs and her weight went as low as 92lbs. There's a Public Social worker nurse that visit her once a month to check her condition because she has TB (per her philippine medical screening), in short she's so thin because she's doing it to herself. Because she won't listen to us or to her nurse, we asked her first cousin to take care of her. But soon after we left my wife started receiving emails. one email really did caused us slander and here's some of the quote from that email.

"how dare you maltreating your mom like this.hindi ko akalaing maging sira ang ulo mo tulad ng hudas mong asawa,alam namin lahat ang mga ginagawa mo sa mommy mo and we cannot ignore it anymore, ikaw na pinag-aral ng mommy sa isang exclusive school at nakagraduate,eh ganito lang pala ang mangyayari sa iyo ang maging isang malaking tanga at gaga. Hindi ko maintindihan kung bakit nagtitiyaga kang makisama sa hudas mong asawa,hindi mo ba nakikita ang hitsura mo sa salamin at pati mommy mo mamaltratuhin ng ganito. teswa,huwag na huwag na kayong magpapakita dito sa sacramento at ipapapulis ko kayo. nagreport na kami at hintayin nyo na lang ang resulta."

can we sue this person for slander? none of it said is true.

petitioned? where are you?

where did this email come from?