Is it permissible to make ablution without answering the call of nature after waking up?
Washing front and back openings (Istinjaa`) is not a condition for the validity of ablution because it is done to remove Najaasah (impurity), thus if there is no Najaasah, there is no need for that, and then it is permissible to make ablution without answering the call of nature. However, prayer is invalidated if there is Najaasah on the anus ,or the front opening, so it (Najaasah) must be removed for the prayer to become valid, and not the ablution.
Is it permissible for a woman to perform the obligatory prayer immediately after the adhan and before the Iqamah is performed in the mosque?
Praise be to Allah, and peace and blessings be upon our Master, the Messenger of Allah.
Yes, it is permissible for a woman to perform the obligatory (Fard) prayer immediately after the Adhan (call to prayer) and before the Iqamah (call to commence prayer) is performed in the mosque. And Allah the Exalted knows best.
What is the ruling on public street water if it gets on a person's clothes or body?
The default ruling is that public street water is pure (tahir). If one is certain of its impurity (najasa), then a small amount that gets on the lower part of a person's clothes or body is overlooked (excused). And Allah the Almighty knows best.
A woman made a wig for herself from her own [previously shed] hair, which she wears on her head after having lost her hair [due to hair loss]. Is this permissible?
All praise is due to Allah, and peace and blessings be upon our master, the Messenger of Allah ﷺ.
Since the hair belongs to the woman herself, the wig can be removed during the obligatory ghusl (ritual bathing), and part of the head can still be wiped during wuḍū' (ablution), there is no sharī‘ah objection to making this wig — provided she does not appear wearing it in front of non-maḥram men (Any males outside a woman's immediate family whom she is permitted to marry under Islamic law), since it is not permissible for them to look at a woman's detached hair.
It is stated in Rawḍat aṭ-Ṭālibīn wa ‘Umdat al-Muftīn: "Whatever it is not permissible to look at while still attached [to the body] — such as the male genitalia, a free woman's forearm, the hair of her head, and a man's pubic hair, and similar matters — it remains unlawful to look at even after it has been detached [from the body], according to the more correct position (al-aṣaḥḥ)." And Allah, the Exalted, knows best.