Why did Gandhari, a re-incarnation of Mati and a model wife, have to suffer so much?

Question

All the characters of the MHB cast and reap karma--whether from a past life, or their present; but I cannot find a reason that Gandhari should have to suffer so much when she was the ideal wife and incarnate of Mati--who by a thin thread, I see is another name for Saraswati.

One theory-she was "Zinging" Dritarastra with a "see how YOU like being married to a blind woman" bad attitude, and also she felt envy that Kunti delivered while she had to carry her baby for 2 years- I just don't see why her impatience or irritation at finding out her future husband was blind, could cause her to suffer such a horrible life of having envious sons (like her) and watching them get killed.

Three questions:

1. Is Mati another name for Saraswati?
2. Why would such a model mother be punished so severely?
3. Are there any stories about Mati that would explain her karma?

Answer 1

I don't know who exactly the divinity Mati is. She may not necessarily be goddess Saraswati though. So, your question parts - 1 & 3 cannot be answered satisfactorily perhaps.

In any case, why Gandhari had to suffer so much is again something, which cannot be answered definitely. However, for a mother, the worst suffering, in my view, can be losing all of her sons, and Garuda Purāṇa does answer why she lost all 100 sons of hers.

Chapter 125 (Brihaspati Neeti-Saara),

Part 1 - Achara Khanda, Garuda Purāṇa

दशम्येकादशीमिश्रा गान्धार्या समुपोषिता ।
तस्याः पुत्रशतं नष्टं तस्मात्तां परिवर्जयेत् ॥ १,१२५.२ ॥

2. The queen Gandhari fasted (for Ekadashi) on the day of the tenth phase of the moon, and lost her hundred sons in consequence.

English Translation by M.N. Dutt

Gandhari fasted for the Ekadashi, when the moon was both in it's tenth, and eleventh phases. And such an Ekadashi fast is considered inauspicious and may result in suffering, and hence Gandhari was afflicted therefore.

So, one of the reasons for Gandhari's suffering was a wrongfully done Ekadashi fast.