Here's the full quote using his own words: “the excellent companion of his life,” a “precious help to him amid his manifold labours and frequent infirmities.”
Note that there's nothing about love, just that she was a good servant.
Calvin never ceased mourning her.
Apparently because he now had to pay someone to scrub his floors.
Geneva, April 11, 1549 Intelligence of my wife's death has perhaps reached you before now. I do what I can to keep myself from being overwhelmed with grief. My friends also leave nothing undone that may administer relief to my mental suffering. When your brother left, her life was all but despaired of. When the brethren were assembled on Tuesday, they thought it best that we should join together in prayer. This was done. When Abel, in the name of the rest, exhorted her to faith and patience, she briefly (for she was greatly worn) stated her frame of mind. I afterwards added an exhortation, which seemed to me appropriate to the occasion. And then, as she made no allusion to her children, I fearing that, restrained by modesty, she might be feeling an anxiety concerning them, which would cause her greater suffering than the disease itself, declared in the presence of the brethren, that I should henceforth care for them as if they were my own. She replied, "I have already committed them to the Lord." When I replied, that that was not to hinder me from doing my duty, she immediately answered, "If the Lord shall care for them, I know they will be commended to you." Her magnanimity was so great, that she seemed to have already left the world. About the sixth hour of the day, on which she yielded up her soul to the Lord, our brother Bourgouin[9] addressed some pious words to her, and while he was doing so, she spoke aloud, so that all saw her heart was raised far above the world. For these were her words: "O glorious resurrection! O God of Abraham, and all our fathers, in thee have the faithful trusted during so many past ages, and none of them have trusted in vain. I also will hope." These short sentences were rather ejaculated than distinctly spoken. This did not come from the suggestion of others, but from her own reflections, so that she made it obvious in few words what were her own meditations. I had to go out at six o'clock. Having been removed to another apartment after seven, she immediately began to decline. When she felt her voice suddenly failing her, she said: "Let us pray: let us pray. All pray for me." I had not returned. She was unable to speak, and her mind seemed to be troubled. I, having spoken a few words about the love of Christ, the hope of eternal life, concerning our married life, and her departure, engaged in prayer. In full possession of her mind, she both heard the prayer, and attended to it. Before eight she expired, so calmly, that those present could scarcely distinguish between her life and death. I at present control my sorrow so that my duties may not be interfered with…. Adieu, brother, and very excellent friend. May the Lord Jesus strengthen you by his Spirit; and may he support me also under this heavy affliction, which would certainly overcome me had no he, who raises up the prostrate, strengthens the weak, and refreshes the weary, stretched forth his hand from heaven to me. Salute all the brethren and your whole family. --Yours, John Calvin John Calvin to Guillaume Farel [8]
Calvinism and love are rarely associated.