Can a widow claim jointly acquired matrimonial property (harta sepencarian) after her husband dies?

Yes. In Malaysia a widow may file a claim for harta sepencarian in the Syariah Court before the estate is divided by faraid. Harta sepencarian is property acquired jointly during the marriage through direct contribution (money, work) or indirect contribution (running the household, caring for the children). The share decided by the court becomes the widow's own, and only the rest of the husband's property is divided as his estate; from that remainder the widow also receives her fixed share. In polygamy, each wife may claim for her own contribution, and the court assesses it on the evidence. Keep purchase documents and proof of contribution. Procedure differs by state, so refer to your state enactment or a Syarie lawyer.